So I am making a solo RPG based around Dungeon Keeper where you design your own dungeon and get raided by heroes. Here are the rough mechanics of the combat system, which is based around Blood Bowl but using a 3d6 dice system and with positioning mechanics adjusted for theater of mind or using simple tokens to keep track of combat. I want it to be complex enough that there's lots of room for variety in monsters, as well as upgrades and improvement. Having Blood Bowl to steal from should make things very easy on that front.

Im mainly worried about the combat becoming tedious or boring. I'm worried that it's too complex. Im also not sure about Groups only getting one attack each, that might slow things down too much. Could any of you tell me what you think of this? Bonus points if you're familiar with Blood Bowl.