Elven Temples (T6) and Colonies (T5) will allow you 27 attacks per full unload, while CoEs (T4) give you 26 attacks.
Why?
Let's have a look at the troop numbers those buildings have (at lvl3) and their respective regeneration rates.
A CoE has 1.300 troops and regenerates at 100 troops per regen (5 minutes), thus takes 65 minutes or 13 regens to fully regenerate. As you lose half of a regen worth of troops (50), you'll have 26 attacks per full unload.
T5 and T6 balanced have 1.100 troops and regenerate at 83 troops per minute. Well, if you multiply 83 by 13, you'll get 1.079 and oops... you're still 21 troops short of a full regen. This means that a full regen will take 70 minutes and the unload will allow you 27 attacks (the last one will however be with much less troops ~8 troops instead of 42).