In table top it works. Smite isn't a spell, so you can use it without any restrictions other than a melee weapon attack. Most beasts have a 'natural' melee weapon and can smite.
Monk abilities like flurry of blows get a little more dicey since technically most beasts can't be unarmed nor wield monk weapons (Apes being the exception). I have no idea how Larian is going to handle that.
