Easier said than done. If he does have a weapon such as a knife, they have just moved within his striking range while he is on his feet and can pivot to counter the move. If you get him on the ground, you can keep his arms pinned against the ground. That is why cops want potentially hostile suspects on the ground. And refusing to show hands is a hostile act.
I really don't see excessive use of force here until after the first tazing - and subsequent tazing could be a function of his refusal to obey requests throughout the incident. I think the kicking while handcuffed and after being tazed is what will get these deputies in trouble.
His defense lawyer lied in the article as well - he claimed the perp obeyed all requests, when he did not follow the biggie that triggered this - and escalated an otherwise manageable incident. Throw in his history of being a drunken idiot who was arrested for drunkenly walking into someone's house - which probably meant he must have refused to leave for the incident to reach the point of an arrest - and you are talking about the kind of obnoxious moron that makes up some of the worst of cop calls.
Quit Resisting....Settle Down!