Another way to make larger combats less of a slog and more snappy and fun, would be to make things like Goblins easier to kill. I don't know if the game has level scaling (though I imagine it probably does), but goblins shouldn't level with me to be on par or just barely weaker than me when I'm level 8 or whatever. They should already be decently weak enemies that my PC's can take out without too many issues, and as I level up and get more powerful they should become trivial monsters based on the fact that they're goblins, not based on the area I find them in. If a bunch of goblins try to jump 4 level 8 adventurers, they should get absolutely slaughtered, not put up a decent fight.
Anyway, got a bit sidetracked but the point I'm going for is to make weaker monsters like goblins actually feel weak. It shouldn't take my fighter 3 or 4 hits to kill a goblin when in PnP 5e my fighter or barbarian should be decapitating goblins left and right with no problem. Flinging a horde of 20 goblins at my party wouldn't be a slog if my characters could easily kill 1 or 2 each per round, or even 4 to 5 goblins with a decent AoE spell from the wizard. Just make combat faster and more lethal against weak monsters like goblins, and you can fling a whole army of the buggers at us in later levels.
