You are doing it wrong.
"Increase to 79 direct SESNA"
"unable due fuel management"
"Roger, hold at NANSU, left hand pattern, inbound on present heading, 2 minute legs. Expect one pattern"."
If the comeback is "cannot hold due fuel"
"Roger, descend to FL230" and co-ord that.
You can't have EVERYONE doing the speed they want, direct to the field. If QR want to run their 320s with minimum fuel and requiring no delay, they should pass that information on and allow for the extra delays on the other fleets.