Seems maybe like the min is enough to get to lvl 15 (where everybody should be at if they have done all activities they could and used no crystals or $) but still not sure if you get more if stl was higher as people reporting differently.
If they dont give enough to go higher than it hurts your coliseum team as the summons will be at ig90 lvl rather than what stl is up to.
if they do give enough to take higher to match stl than it changes the value equation of whether to invest earlier in an era since materials you buy will multiply with each new marquee toon