You might see the dragnet parable a little differently if you see the 'sorting-of-the-fish' portion as starting at the end of the age, but as continuing throughout the Millennium. The wording allows for that view, that is, the sorting begins at "the end of the age." (That "the end of the age" or "the conclusion of the system of things" does NOT mean "the last days" can be seen from a comparison of Mt 13:30 with Mt 13:40-42 where the "end of the age" begins with the weeds being collected and burned "first." Also, "the last days", according to NT writers, begins at Jesus' first advent. Compare, for example, Heb 1:2. See also this post
for additional on how NT writers viewed the "last days.")
Moreover, compare Acts 17:30-31 where Paul says that "all mankind, everywhere" were being called on to "repent" in connection with the good news that was being preached even then in the 1st century. (See here
regarding Acts 17:30-32.) That would argue that the dragnet was already on its way to being dragged among all of humanity. And both the wheat & weeds parable and the dragnet have both good and bad associating with the good news, arguing for a similar time of application.
The parable of the dragnet starts with the illustrative part. The kingdom of the heavens is like:
1. A dragnet that pulls through the water catching fish of all sorts. (Mt 13:47)
2. When full, it is pulled on shore and the fish are sorted. (Mt 13:48)
In the application (Mt 13:49-50), Jesus picks up at point # 2 with the net already on shore and the angels separating the catch "at the end of the age."
The period in which the dragnet scours the sea can be seen as covering the entire range of the Christian era if one sees "the end of the age" to continue on into the Millennium. This application would include ones "caught" by the dragnet during the many centuries of the Christian era. It would also give meaning and purpose to the preaching of the disciples during the whole of the Christian era.
One other indication that the Wheat & Weeds parable and the Dragnet parable have a similar time frame of application is the fact that Matthew (or Jesus himself) has arranged what we now call chapter 13 into a chiasm or symmetry with these two parables in complimentary (i.e. symmetrical/chiastic) positions.
From Constable's Notes
As elsewhere in Matthew, references to the kingdom indicate the future messianic (millennial) kingdom. However, Jesus taught some things here about the unseen growth and development of the kingdom in the inter-advent age that precede the establishment of that kingdom.
Matthew presented this discourse in a chiastic (crossing) structure,” New Testament Studies 25 (1979):516-22.
This structure is common in the Old Testament and in other Jewish writings. It enhances the unity of the discourse and focuses attention on the central element as what is most important. A diagram of this structure follows.
A. The introduction (Mt 13:1-2)
. . . B. The first parable to the crowds (Mt 13:3-9) (Sower)
. . . . . . C. An explanatory interlude: purpose and explanation (Mt 13:10-23)
. . . . . . . . . D. Three more parables to the crowd (Mt 13:24-33) (Wheat/Weeds, Mustard, Leaven)
. . . . . . . . . . . . E. An explanatory interlude: fulfillment and explanation (Mt 13:34-43)
. . . . . . . . . D^ Three parables to the disciples (Mt 13:44-48) (Treasure, Pearl, Dragnet)
. . . . . . C^ An explanatory interlude: explanation and response (Mt 13:49-51)
. . . B^ The last parable to the disciples (Mt 13:52) (Home Owner)
A^ The conclusion (Mt 13:53)
This structural analysis reveals that the discourse consists of two sections of four parables each, the first four to the multitudes and the last four to the disciples. In each section one parable stands out from the others. In the first group this is the first parable and in the second group it is the last one. The central section between the two groups of parables explains the function of the parables and explains one of them.
With regard to the Wheat and Weeds and the Dragnet, both occupy the complementary/symmetrical positions within the chiasm. Both elicit explanations from Jesus, whereas the two following the Wheat and Weeds do not. And the two preceding the Dragnet do not. All of the parables in chapter 13 appear to refer to circumstances within the entirety of the Christian era.
The Mustard Seed and Leaven parables appear to describe the kingdom from an overview position. Their counterparts, the Hidden Treasure and the Pearl of High Value present the kingdom from an individual viewpoint.
The Wheat & Weeds and the Dragnet present the Christian era both during and after the end of the age. In the Wheat and Weeds, note the allusion to Dan 12:1-3 in Mt 13:39-43. The corresponding part in the Dragnet parable would be the angels doing the separating work in Mt 13:49-50. The 'shining of the righteous ones' in Mt 13:43 is an allusion to Dan 12:3 which has the resurrection as its backdrop in Dan 12:2. Thus, the 'sorting' done by the angels in the Dragnet parable, as a parallel to Mt 13:43, has its background based in both the great tribulation and the period that follows. The parallel part of the Wheat and Weeds (Mt 13:43) would show that the wheat that will be involved in the 'sorting' during the Millennium.
During the current Christian era, the Wheat and Weeds parable shows how the good and bad came to 'grow together.' The parallel, the dragnet, it scoops up 'all kinds of fish.' The two parables are quite complementary of each other.
We could graph out the two parables that make up B & B^ and the six parables that make up D & D^ thusly:
┌ B. Sower (Mt 13:3-9) . . . . . . . . . . . . . . ┐
│ ┌ D1. Wheat and Weeds (Mt 13:24-30) . . .│ First 4 parables given to the crowds
│ │ ┌ D2. Mustard Seed (Mt 13:31-32) . . . . │
│ │ │
│ │ │ ┌ D3. 'Hidden' Leaven (Mt 13:33). . . .┘
│ │ │ │
│ │ │ └ D3^ Hidden Treasure (Mt 13:44). . .┐
│ │ │
│ │ └ D2^ Valuable Pearl (Mt 13:45-46). . . │ Last 4 parables given to the disciples
│ └ D1^ Dragnet (Mt 13:47-48). . . . . . . . . │
└ B^ Home Owner (Mt 13:52) . . . . . . . . . . ┘
The Leaven and the Hidden Treasure are linked by the things 'hidden.' The leaven is "hidden" in the dough, and the treasure is "hidden" in the field.
The Mustard Seed and the Pearl are related in both by the movement from small to great. The mustard seed becomes a 'great' vegetable, and the found pearl is of very 'great' value.
It does appear that there is a very deliberate structuring of the parables in Matthew 13. I'm going to have to look more at this. (Incidentally, I already have this chiasm posted here
. But it deserves a lot more scrutiny.
But back to the point I was making. The chiastic structure here would argue that the dragnet parable portrays the Christian era in its entirety, just as its parallel (the wheat and the weeds) does. That would be my opinion, anyways.
(In referring to Jesus' first advent as the beginning of the last days, see this post
and included links which shows Jesus first advent to be the very center point of the entire 7th rest day.)
Index to Parables
Edited to add:
I added the Sower and House Owner parables to my little ascii graphic above to see visually how they complement each other.
In the Sower, you have Jesus (at least at first) sowing kingdom seed. It affects some so that they 'sprout' and themselves become productive at varying levels.
On the complimentary side you have 'every instructor who has been well trained for the kingdom' bringing out 'things new and old', presumably, in his instructing others about the kingdom.