I actually think people are too blase about us losing Gyokeres. Losing him would be a massive, massive issue in terms of filling what he's given us, so consistently, the past two seasons. It's also arguable that teams doubling, trebling up on Gyokeres has given Hamer the space to excel. If we lose Goyokeres and they switch their attention to Hamer, will he do as well? tbf if he did, then he would truly be exceptional but it's asking a lot, and would probably be unreasonable.
I'd have hopes that we could strengthen the team overall though - might need a season of bedding in so I'd fully expect to see growing pains, but then it's asking an awful lot for both Gyokeres and Hamer to do so well for us and play so many games next season if they were still here next season I couldn't see us getting near the playoffs next season if they stayed either, as this season really is, rationally, a one-off with the team we have.
And back in't day once we signed Hartson in that season we were... alright, but it was too late. Watching us launch long kicks up to Bellamy was laughable really, and Strachan showed himself totally unadaptable. Robins might not change much during games, but with Viveash he's shown himself flexible in changing the way the team plays to fit with the players we have. Not saying it's easy, but frankly I find the thought of missing Gyokeres's punch and dynamism far worse and far more of a challenge. We're going to have to change system and style really, because we just won't find the same.