I think we could come to a compromise, because switching weapons instantly is how i do it in 5e and i think it makes the combat run a bit smoother than it would to waste resources on it. An action to swap weapons is too much whenever every other member kills the enemy before your next turn. Perhaps there could be a gameplay option to toggle between instantaneous switching or bonus action switching weapons, but maybe that's incompatible for the rest of the game.
5e rules allow you to draw as part of the action to attack, and rather than everybody dropping their weapons like litterbugs we just generally ignore drawing/stowing rules unless somebody takes it to some extreme.
