Hello Rmean,
If you use Policing the exceeding traffic will be dropped and ofcourse as TCP is reliable there will be retransmissions,etc but the ASA will allow them as long as they are not exceeding the parameter previously setup.
Nor you could try to use Shappin ( ASA will not drop the traffic, the traffic will be buffered so it can be sent later)
Any other question.,.Sure..Just remember to rate all of my answers
Julio
Julio Carvajal
Senior Network Security and Core Specialist
CCIE #42930, 2xCCNP, JNCIP-SEC