I’m not advocating reckless use of your forces but this game requires player’s to take more risks than other A&A games. I think that Revised lends itself more to a “What will I lose” thinking while BOTB needs to be “What will I gain” thinking. I’ll admit that is a very subtle difference and perhaps simply one of semantics.
In BOTB things don’t have a cost measured in IPCs so a unit’s value or expendability becomes much more situational. You are buying things (ground and time) with the units and you must know when to pay the price and not be afraid to do so.
Put another way, be more concerened with the sure paths to defeat than the uncertain paths to victory. Playing in ways that only preserve your forces is more a sure path to defeat in BOTB than it is in Revised, Pacific and Europe.