User blog comment:Crimson Storm Mich/Future Units Preview v2/@comment-29210801-20170523223130/@comment-31529105-20170524070050

Even though Owen and Grah are more than capable of fighting the 4 fallen gods, they are both quite old, so they probably sent your summonr and friends on the god-slaying adventure to mature the summoners tallents so that they would have capable successors.