Firstly, I would say that Cocu has not lost "our best 3 players from last season". We as fans have. DCFC as a club have. But they were not here when he arrived, and were never realistically likely to be, so he would have known the score, with regards to the available playing staff, and would have known he was never likely to have Mount, Tomori and Wilson as options. So he's "lost" nothing, from what I can see!
As for his achievements thus far, arguably he has achieved very little, but even under "normal circumstances", that wouldn't be too disconcerting, given the fact he's only been here 5 minutes!
However, having been dealt the cards he has thus far since arriving, much of which would not... and could not... have been foreseen by anyone, be that club staff or fans, I would say he's brought a mature, calming influence, with a huge dollop of class!
I'd argue further that he may well have even saved the public face of our beloved club, as without him, we may have come across as a little bit more scummy, to many more oppo fans, than we currently do!
Hopefully, that's all behind us now, and hopefully, Mr Cocu can now concentrate on doing what he was brought in to do... and hopefully his achievements will be more apparent, come May.
I have to say... I have high hopes.