I've run a couple of MegaMek/MekHQ campaigns where I use a lance of 'Mechs and two lances of vehicles. Each combat used either one or two lances, chosen at random, so I frequently ended up with either vehicle only, or combined arms, battles.
I find it easy to immobilize vehicles, but finishing them off can be costly. Ideally, for taking out such "impromptu turrets", I like to use a mix of direct-fire and LRM units, so I can either use spotted indirect fire against them without taking return fire, or else concentrate aimed shots at weaker locations, depending on the target. In a mercenary campaign, destroying the turret gives you a salvagable and repairable hull, and punching through the side or rear armor of a similar second unit gives you a salvagable turret to fix the first.
Infantry, on the other hand, really doesn't work all that well by itself in BT. In an urban scenario, both sides will want to use buildings for cover, and you don't shoot at the troops, you can only shoot at the building they're in, with its immobile target modifier. In essence, you can't miss, and neither can they, and it all boils down to the CF of your building versus the CF of the opponent's, and knowing when to bail out and find another building before the one you're in collapses. Not a lot of tactics behind it, and certainly not very realistic. In the open, either all of your weapons hit, or they all miss, and the first one to get a lucky die roll has a massive advantage for the rest of the combat. Again, not so much tactics as the luck of the dice, and again very unrealistic.
