This make sense to me as well. He's capable and Hi Shin Unit doesn't lack in strong martial might. Shin and Kyoukai themselves are enough, but Ten is not at that level as Strategist. Ma Ron isn't that best that Ten will get completely shadowed but enough that it'll help Hi Shin Unit.
That said, it doesn't hurt to add more brain power.
Were it up to me entirely the 60K HSU would look a bit like:
Kyou Kai on attacking wing with 15K
Shin in the centre with 20K
Heki on defending wing with 15K
Ma Ron in the reserve with 5K