Yes I agree with all of that.
My concern re Walsh came initially when he seemed to suggest his role was being around training a fair bit etc. I can't imagine Brands ever doing that, there is a clear separation in how he operates. It's very clear what his remit is and what his remit isn't. Being a sort of assistant manager sort (like Walsh was at Leicester) wasn't it.
There's no doubt to me he was undermined. We got him in late in the first window and it is my understanding he had an accident that made it difficult for him. In that vacuum a mixture of Koeman, Moshiri & Kenwright/Elstone began to step in and rather than having 1 plan outlined by Walsh we seemed to have 4 or 5 different ideas all merging together. In many ways I'd say the first summer window was worse than the 2nd, but Lukaku's 25 goals covered it up. Having a lad scoring 25 goals will cover a variety of sins.
Even when Brands was appointed, the Echo wrote that his remit would be different, and Walsh's was to "bring in young players" or something equivalent. How had that become his remit? That can't have been the remit he was recruited on. The likelihood to me would have been, with the force of character of Koeman and to a degree Kenwright a guy who naturally seemed at ease in the background snuck back their and allowed for a compromise to be in existence whereby he brought young players in and Koeman got what he wanted for the first team.
We've all probably done that too. When a forceful character is somewhere caved in to them and given them what they wanted. But within a business context it rarely works out well.
In fairness it's probably true to say that many of Walsh's signings could have been good, but he had some duds too. Gabbiadini has been a flop (though it smacked of a panic buy) Belfodil has done very little and in truth Sandro has been a poor buy (and that is a Walsh buy). So it's not all positives. However Koeman's insistence on PL experienced players (which lets face it are the ones he wanted) have been as a rule much worse. That to me is the quite clear demarcation in recruitment we have (with the marquee names being thrown in by Moshiri i.e. Coulibaly and Witsel).
Williams, Schneiderlin, Bolasie, Klaassen have all been poor buys while it's taken Silva to rescue Keane (but Pickford has done well). But yes had we looked for cheaper alternatives to all of the above and had more of a mixture of Walsh's signings he may have been ok.