We don't really have a culture of cheerleaders here in the UK, but i think i know what you mean...
If you want the tempo to be standardised between pieces in the montage (much like a DJ set, then Logic may not be the easiest way to do this, but...
You need to figure out the tempo of each piece of music, you can either timestretch the region to fit the desired tempo:
1. Import the piece of audio into Logic.
2. You don't know the tempo, listen to it and cut out a four bar region of it.
3. Drag it to a new track on Bar 1.
4. If it matches the four bars of your existing tempo in Logic - wow - you've been lucky ;)
Otherwise change the tempo in the Transport to the tempo you want the region to play at.
5. Set the locators from 1 1 1 1 to 5 1 1 1 ( a four bar loop)
6. Go to local menu:
Audio > Adjust region length to locators
7. Listen to the end result - and if it's not great, try some of the different algorithms in Audio > Time Machine Algorithms>
or you can convert each region into an Apple Loop:
1. Find the tempo of the region either using the BPM plug-in. Or
2. cut out a perfect four bar loop from the region.
3. Place it at Bar 1 on a new track.
4. Set the locators to cover bar 1 to 5.
5. Go to Options > Tempo > Adjust tempo using region length and locators
6. Select "Globally" from the new window and your project tempo changes to the tempo of the region.
Now convert the main region into an Apple loop making it a looping apple loop and re-import the apple loop version.
You'll need to do this for all of the pieces in the montage if you want the project tempo to remain the same.
For much much clearer steps and more explanation I'd really recommend the Logic 101: Core Logic 8 tutorial video:
Chapters 42-52 deal with time stretching in detail and chapters 72-78 deal with Apple Loop Creation.
If you need any further help, let us know ;)