I want to just say one thing. I noticed some people use 'difficulty' as ticked to 'nerf x,y'.
You can complete game on tactician without: - 'barrelmancy' - minmaxing - using speed potions - using haste - using fireball - tavern brawler and any other feat or weirdo playstyle's - multiclassing
It's possible, you can do this. But i recommend life domain cleric as hard support for this kind of run.