Only the area commanders make such recommendations (through the chain of command) and those officers have not requested additional troops.
After Shinseki--then Chief of Staff--said that an Iraqi occupation would require 250,000-300,000 troops and got publicly reamed for it by Rumsfeld, Cheney and Wolfowitz, everyone in the chain of command knew what the score was and what would happen to them if they said that they needed more troops than we could send. They didn't get to the high positions they are in without being adept politicians and knowing what their constituency wants them to say.