I kinda agree with you Bob. I'm not the least bit of a co-regencist (reread militantly opposed to it. It's nothing more than an excuse to cover up gaps in the historical record or explain away atypical artwork. Or prop up some lame theory. I'm going on one of my rants here so I'll stop.) However the skeletal remains that are preserved strongly suggest that possibility. Tut was 19 Smenkhare 20 or 21 (assuming it's tut.) Kiya's canopic looks incredibly young (allowing for artistic conventions.). In addition to that the Amarna letters make it pretty clear that all the bride trading was for young girls who had probably just reached puberty. 13 or 14 maybe 15 tops. We might have to revise Akhs age from the 40 or so that is attributed to him back down to 30 or so maybe even younger.