It's my understanding that we were some amount of loaned unit levels to start, and are granted several (currently 2) daily via our inbox. After that, the only way to get additional loaned unit levels was through starring up the marquee and getting to the additional levels of the marquee event.
However, I can see within my shard, I have a 6 star r5 and level 29 loaned units. However, other people that are above me on the leaderboard have a 5 star marquee and more loaned unit levels.
Is this a known issue that's being looked into? The primary source of damage at this point of the coliseum is the loaned units. And when you are at a disadvantage because the system hasn't given you the resources you've earned, there's no reason to bother engaging.
While we're at it, can we add a "COLISEUM" tag so we can accurately tag these posts.