While either is fine individually for the most part, I'm afraid him and Maddison can't coexist against most teams in this league. Neither is exemplary in terms of defensive positioning and discipline, and while Bergvall mostly makes up for it with his great workrate it still puts too much strain on the DM behind them. Especially if the DM in question is someone like Bentancur who can barely move.
His physical prowess, his tendency to roam around, and his ability to carry the ball forward with his dribbling all remind me of Dembele and Gerrard. The former started his career way up front before gradually finding his way to a deeper role, while the latter started in a relatively deeper role before having his career year(s) playing right behind Torres as an AM.
I can see Bergvall following either one of those trajectories.