True Qben, But....... (you knew there was one, haha) In our department,,,,,,,, If you are luckey enough to be hired without being a paramedic you can loose your job if you fail too pass the state and national regeristery.
So there is a little less pressure on you if you don't have to worry about your job, by being a paramedic at the time of hiring. Add in the fact that you are still learning to be a fireman it's a little more difficult to due both at once.
As a added bonus, a lot of fire departments give 10% to you overall score if you are a paramedic compaired to 3% for just EMT.
There is also a BIG trend to hire only "Paramedic's" because they are ready to hit the streets now instead of "a year from now" add to that the added expense of training and you can see why some cities only give there tests to "Paramedic" canditates.
I can only speak from my experance as a medium sized fire department Officer (400 man dept.) with 22 years on the job.
BB