Your point is based on the transfer free paid for Benatia which is flawed at best and the comparison with Castan who held a regular place in Zeman's team due to solid performances, but was apparently average and only got better this season due to Roma's system, just like Benatia which you're trying to point out.
So your real arguments still stands at: Valuation of a player, low transfer fee which got much higher after a season where he got international recognition = cant be THAT good and his defensive partner Leandro Castan who was average before (your words), but had a fine season now so it must be because of the Roma system since apparently a player cant improve.
And while Benatia is hyped a lot around here on this forum and while im guilty of this as well, I doubt many here see him as a second coming of Jesus, but more of a very good defender who is somewhat available in a market where its very difficult to get an experienced top class centre back since most of them already play for a team who wont sell at any cost.
Those are not facts by any means, those are your opinions, just like these are my opinions.
And if you think I insulted you then I apologise because I never intended to do so, but I disagree with your opinion and your arguments and that's it.