Engineers in Assaults

[Steel God]

Okay....not too long ago I made a statement on the WDS Boards which turned out to be wrong....and if you had asked me to bet any amount of money on it prior I would have taken the wager without hesitation.  My statement was that Engineers when added to an assault attack (the reference was for FWWC but I believed it would apply to PzC and/or MC as well) would have the effect of lowering casualties for the attacker and therefore increasing the chances of winning the assaults.  I believed this so strongly that it effected the way I played, I husbanded my engineers and saved them for critical assaults because of this belief.  Now, I don't mind being wrong and/or corrected, but this idea is so ingrained in me I'd love to understand why I thought it was so.  Did I dream this up out of thin air, or has anyone else played a game (WDS or other) where Engineers provided that sort of assistance I'm thinking of?  I'd blame advancing age and senility if I haven't believed this for years or decades.