I don't think his appointment was ever going to herald a conveyor belt of signings in the short-term. His role as I see it is to plan for the long-term success and sustainability of the club on the field, and like any other element of rebuilding, that can't be done overnight.
Although most DOF appointments are short-lived, the intention at least is for it to be a longer-term appointment than the manager, otherwise it makes no sense. I hope he stays for at least 5 years and beds down structures that serve us for many years after.
I am not clear on what his role precisely entails, but we do know that scouting and recruitment are the major elements of it. If he takes credit for Gana and Lookman, then he has unearthed at least one if not two excellent signings for us already, pretty good progress in my book.
I think he can only be judged fairly over a couple of seasons. He will be hailed as a genius if Lookman does as well as some are expecting, and if the likes of Donkor signs permanently and has a similar impact. Koeman's interest will be more in signings that can make an immediate impact, and some signings will progress quicker than expected, Lookman being the big hope.
A worry is the continuing role that Kenwright and/or Elstone appear to have. Perhaps SW is a bit wet behind the ears when it comes to actual negotiations, and the "business" side of football, if so, then we obviously have to delegate in that area but I would like Elstone to be replaced at least. We saw the effect of too much overlapping of roles and duplication of effort last summer.
I do think though in an overall sense, the Director of Football has to carry the can for the overall success/failure of football operations, outside of immediate results, but particularly for transfers. He may have to assert his will over Kenwright/Elstone to make progress, and if that's the case, I hope he has Moshiri's support.
If we fail to make the required impact in the summer, I think Walsh should be the first port of call for an explanation as to why.