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To answer part of your question, the only control you have over what items you bring into Fights is whatever your character is personally armed with. Otherwise your Mobsters will be outfitted with the most powerful weapons, armor and vehicles that you have remaining in your Stockpile. So chances are you have a couple items that are more powerful than the Steel Baseball Bat and those are being used instead.
Take a look at this screen shot from a recent Fight.
I bought 10 Crowbars to use in Fights but I had some Boss drops (Taser, Machete) and an extra baseball bat in my stockpile. You'll notice it lists the items brought into battle in order of their combined strength (Att + Def). So out of the 10 Crowbars I bought only 7 were used because I had more powerful items at my disposal.
Hope that helps
Last edited: Aug 13, 2011