The additional T5 troops will be given away based on recent losses and participation in CZ's.
If you're looking for better troops (and who isn't?!) please participate in CZ's. Even bringing T1 troops is OK, at the least, you get to see how defense/attacks are done and will be prepared when higher level troops are created by your civilization.
Lastly, please take a look at the Gallery Picture listed as "Entrance Blocked". This is how CZ should be defended.