Dave you not considered the fact that maybe Koeman does see Ross that way, but right now maybe Koeman believes he neds a lot of work done in training to round out neglected parts of his game which he basically needs in order to play that position effectively and consistantly? - Barkley for the past 3 seasons has been hporribly managed as far as rounding his game out - and fitness wise (evidenced by the stupidly large amount of weight - muscle he was allowed to put on last season) - think he will eventually go into that box to box role, but will need more than 3 weeks training with Koeman before he can be played there really.
As for pressing mate - yeah most players can be tasught to press decently, but to press at the very top level requires a bit more than that - otherwise players like Kante wouldn't be getting bought for 30+ million mate by very good coaches. Certain players just havea knack for it, for intercepting balls and for generally being very effective at stopping the opposition getting any rythm (early doors but Gueye doe slook one of those - and his stats suggested he could be from last season and his time in France as well)