I might just agree Tshiunza is a lock option, having met him in Nice during the RWC though he isnt that big. I'm 6'5 and hes about my height.
We have a host of young locks around currently, Teddy William's, Jenkins, Fender, Carter... all are probably taller than Tshiunza, and I'd argue all but Fender are better lock options ahead of him (for now).
Tshiunza is very mobile, why have him compete with 4/5 good options, when we can risk developing him into a ball carrying back row.
People keep saying we are blessed with back rows, I think we are as weak as we have been in ages. Reffell is hardly world class, Wainwright is a good player, but 8 he is not anywhere near as effective, Basham isnt going to be world beating. Infact only Jac Morgan has shown potential to be top class, everyone behind himself has pretty hefty flaws.
I say take the risk with Tshiunza!