In terms of the squad, I think there are three elements to it: quality, injuries and tactics.
Last year, we clearly had the tactics (and the training to go with them) badly wrong. We can hope that Gustard has learned from his time with Eddie how to make a rapid change in tactics.
Squad quality is actually higher than I can remember. With everyone fit, we can field a XXIII that has 14 internationals (Marler, Elia, Sinckler, Horwill, Robshaw, Clifford, Bothma, Care, Saili, Tapuai, Visser, Brown, Collier, Luamanu) and several others who are expected to get international recognition before long (Smith, Marchant, Boyce, possibly Baby Chis).
We will need to replace Horwill, Robshaw, Care and Brown, probably by the end of 2019-20. Between Clifford, Wallace, Baby Chis, Waters and Morris we have the latter three fairly well covered; the open question is where our next lot of locks are coming from. We don’t know whether Dombrandt and Symonds will step up, but Merrick has shown a lot of potential.
The big issue is injuries. We don’t seem to be able to keep the same hooker fit from week to week, let alone the same team. Clifford, Bothma, Wallace, Saili, Collier, Luamanu, Marchant, Baby Chis, Big Chis, Buchanan... it would almost be easier to list the players who have stayed fit than those who haven’t.
We’ve struggled with a long sicklist and in particular squad continuity since 2012. I don’t know why. We’ve also managed to recruit a lot of players who’ve then spent most of their Quins careers on the treatment table. I don’t know why that is. We’ve certainly managed to rehabilitate players in the past - Ollie Kohn was, IIRC, recovering from a very bad knee injury when we recruited him and went on to be a great player for us.
I don’t have a great sense of whether other teams struggle the way we do; it doesn’t feel that way. I suspect our injury problems the last few seasons have been so deep that we’ve been forced into rushing players back and having them get injured so the cycle begins all over again.
I don’t know if Gustard (or perhaps more likely Millard) can do anything about that - but I suspect that that’s the key problem to fix and we are good enough to compete if we can do that. (But it’s worth noting that in the GP “compete” means exactly that: there are no pushovers any more).