3rdtimelucky.
I can't speak about the specific places you've mentioned, but something to bear in mind is that ATC sequences based on groundspeed. This is something that I've noticed is lost, because everyone talks about IAS. Are you at a lower level than the jets you are talking about?
Some other points about sequencing-
-Props are much more flexible than jets. It is far easier to slow a prop than a jet.
-Less overall delay will be caused by telling the jet to go fast and the prop to slow, than vice versa, because you have flexability at both ends of the speed range. The prop cannot speed up to 300kts.
-The 'natural' sequence will usually define the landing order. ie. If untouched, what would happen? If left alone, the jet would reach the field first, then ATC will make that happen, just with the required spacing added. If you mess with this, you are just making your job harder.
-Economic imperitive. This is becoming more a factor these days. The greater good, for the larger number. ie if it's a dead heat, it will cost more money to delay the jet (I realise this will be unfair if the prop is copping the delay every day, and the jet never does. One has to be careful in making that sort of accusation, as every pilot thinks he is being discriminated against. Often, you are not privy to the delay being given to other aircraft- the jet will probably get a speed restriction higher up on another freq and you never hear it, then claim the jet is never delayed).
-Runway use. Are other aircraft waiting to depart? Wake turb comes into it.
I sequence all day every day, and these are the 'big picture' things that I find pilots sometimes don't see.