Without more of the "new bits of info" its a difficult one to answer.
There are 1000 answers to this question.
Lets say for example, you have one runway (wind is strong so you can only really use the one direction), they are all IFR, they are all going to the same place and they are all ready to depart right now;
I'd send the fastest one first, then the second fastest, then the last one.
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If they were going different directions, ie left turn out/right out turn out;
I'd use the format, left, right, left, right, fastest one first.
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If the cessna was a training flight, this would get a lower priority and go behind the other aircraft.
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With regards to vortex;
The best way would be to let the smallest one go first, but then, assuming they are on the same route, you'll have to wait for the smaller one (and probably slower one) to be sufficiently out of the way to launch the bigger (and maybe faster one) up his chuff.
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There are litterally 100's of other reasons and rights/wrongs in answer to this question though. BTW; during the tech interview, IT IS ok to change your mind once they reveal more of the info. (a controller is allowed to change his mind in real life after all).
Hope this helps.
Bri.
Traaaaaa.