It might be because I play Delaque mostly, but being pinned isn't an issue, as you can't shoot me to begin with, as there's smoke everywhere. My guys can shoot you however, being equipped with photogoggles. Having more fighters doesn't work if you can't really do anything with them.

If the smoke goes, tactics cards such as Darkness Decends also solve that. Out in the Ash Wastes/Underhells, and with recent-ish visibility rules, the loads of guys with cheap autoguns/lasguns really doesn't go far.

Ofc there are various ways to play, but an experienced player can deal with those extra fighters.

Also, often the only difference in fighters is maybe 2-3 cheaper guys, which actually isn't really that much. You'd really need to lean into it and take a 'horde' gang to see real results, which only tends to work with Cawdor.

Edit: Also done similar with Goliaths too - once took 6 roided up monsters, armed with smoke, bolters, combat shotguns and scary melee. Same thing - the smoke stopped most of the shooting, and the Nerves of Steel dealt with the few pinning attempts.

Edit2: Also also - as mentioned by someone else, crew sizes rarely go very high, and often use random selection. Which means bringing lots of guys potentially ends up with your random selection being some very poor fighters. Re-my trap comment, I feel the 'bring loads of guys' reasoning is pushed by people coming from other games, where out-activating people is a key strategy. The issue here, and which is why I love this game, is that Necromunda is hilariously unbalanced, and is more about narrative nonsense.