I like that more attack slots makes low tier units a credible threat throughout the game and that armies of enemies are incredibly dangerous to even a fully maxed fighter if they're caught alone, but it also trivialises many fights in a really anticlimactic way and tends to turn every battle into a tight messy blobfest and just generally detracts from the combat experience. Unless you're playing starcraft, I think one slot is best - maybe two could be okay? I just wish it was a more modular variable, like being able to change it for specific character types rather than whole race types, and being able to set the number of outgoing attacks, rather than it only setting the number of possible incoming attacks.