Tony Vargas
Legend
if we're going to have that fantasy of wading through large numbers of monsters...well...we need rules that make that tenable and not exhausting for the GM and a drag on game play.
Fair.Not really. Because running theses mooks wouldn't even really reinforce the fighter core fantasy.
The one thing fighters do really well in 5e is single target damage. Adding more targets, even weak ones is a direct dilution of the fighter's impact on the battle. Adding 10 or 20 of them means adding the type of threat a 5e fighter has the most difficult time addressing (outside of flying creatures).
D&D may not have done a great job of the whole wading through large numbers of monsters power fantasy....

TSR D&D, the fighter had the ability to attack less-than-1-HD monsters (like goblins and kobolds) once per round per level, and, with 7 hp, tops, a pretty good chance of one-shotting each of them. Problem was those were litterally the least of monsters, they'd have a bit of trouble hitting a 1st level fighter in splint armor, by the time you were mowing through them they were irrelevant, and spells could just anihilate large numbers of them.
3e, the Fighter could get Great Cleave by 4th or WWA by 6th, and mow through groups of enemies if he could one-shot them individually, and reach could help make that group bigger. But monsters you could hit & one-shot dependably w/Great Cleave were, again, pretty quickly irrelevant and could be erased even more efficiently by AE spells. 3e also introduced a way to handle large groups of enemies more easily, swarms. Problem was they took half damage from single-target attacks (full or extra damage vs attacks that could target the whole swarm), so Great Cleave was no help, and WWA could be ruled either way.
4e kept swarms and introduced the fighter got at-will cleave and encounter and daily attack powers that could include mulitple attacks or a small AE, and even a small AE worked well against swarms or/and minions. Of course, casters, particularly Controller-Role casters like the Wizard, still got bigger AEs, and there was no martial controller.
5e fighters specialize in single-target DPR via mutliple attacks like Action Surge and Extra Attack, but no AEs, minions are gone, so it's back to one-hit-kill as the threshold for mowing through monsters - BA makes those monsters less trivial a threat, but they're still efficiently erased by AE spells. There are still swarms, so a large group of enemies modeled by a swarm can be subjected to the fighters single-target DPR, but it resits that damage.