That's the most amusing part. He doesn't waste shots, per se. He just makes inadvisable moves to get the shots. Damn near every shot he took was a "good" shot as long as you ignore the fact the blackjack was likely going to get hit back by everything left on the battlefield. He survives all that though, and then gets obliterated because he kept using it as a battering ram. It's a tactic that can work perfectly fine in a skirmish, but will probably get you bankrupt in the campaign.
I think that was more due to tunnel vision. He completely forgot about placement and firing and just headbutted, because he was getting worried about ammo/another boss-mech popping up after he finished the others.
I'm really enjoying his approach. He knows a *little* about the lore and a few basic tactic from playing Mechwarrior 2 when he was a kid, but the rest is a learning experience. he makes stupid mistakes that I wouldn't, but I like to see what the result of those mistakes are in case I'm wrong.