Clearing two aircraft into the hold at the same level is a sure invitation for Mr Murphy to put in an unwelcome appearance. It may be seen as acceptable by some of the more gung-ho guys, but as you get older you become much more wary of the insidious ways the wily Murphy can creep up on you.
I once got totally maxed out during a mass F-111 recovery into Lakenheath, but managed to squeeze a vital couple of aircraft into the top of the hold by using 500ft levels. Certainly not SOP, but done by using 'experience, trust, faith and self-belief'.
Perhaps this might be an unofficial solution to the OP's scenario. Better 500ft separation than a paint job.