>

They have somewhere around 20000 trained troops. Not enough to make strategic difference, not to mention that most will make a 180 degree turn and join Ukraine's Armed Forces. Lukashenko knows that and that's the reason he's still on the fence whether he wants to attack or not.
It's like they they want their excuse to enter the war to be as flimsy as possible >

It would damage Russia to let Belarus to enter the war. >

They, (Russia), could blame Belarus for "incompetence" if something else goes wrong.
Plus they would have more cannon fodder to throw at Ukraine ... >

Belarus has nothing to offer in terms of war >

I don't know for sure, but they offer Russia 2 things.
1) More bodies to throw in the fire.
2) Some kind of made up legitimacy "look, another country doesn't like Ukraine, so we must be right" >

Army of Belarus is inept, badly trained and has weak morale. We will steamroall over everyone, who'll cross our border. >

So, just like the Russian army?