Exactly right - it's who you buy and how many, look at the number of new players bought in to Fulham, they never coped with the transition.
We need to add gradually and improve incrementally, the idea we buy 4 or 5 players is concerning because you have to give them time, a fair bit of it and that means sacrificing results, which I am guessing none of us would accept either.
Also I find the 'net spend' argument a little bit of a red herring, I was listening to a podcast who made the point that Alexis Sanchez was possibly the most expensive signing for Man United of all time, why? Because the wage level he was offered meant other players would demand parity or an increase in line with that player's wage, so an ongoing cost of millions of pounds, a set of overpaid players who are unsaleable and a team that under performs. Perhaps a salient reason why anyone would struggle to manage the side.
The amount we spend is an irrelevance when compared to creating a sustainable squad that has the depth to handle the games at the business end of the season. We're not there yet and it will take more than next season to get to that point, it takes a long time to be an overnight success.
Actually that does pose another question, would you accept next season as transitional, winning nothing, no Euroean competition, if it meant that we developed a team/squad that could mount a serious challenge on all fronts?