No, if I had the choice personally I’d have him be the HC not the OC and definitely not both at the same time. This is a moot point anyway but you askedI understand you don't want the same guy doing overall game management AND calling plays.
I doubt that is an option here for the time being, irrespective of who is the OC. Your post said you wanted him to hire a "capable" OC. I was just pointing out that that is not really what you want. You want him to give up either the play calling duties or the HC duties. I'm saying that is not realistic at this time.