He's got all the physical attributes to become a decent prem striker, but needs schooling on positional sense, ball striking & decision making. Don't think he'll get that at the blades.
He either needs to be guaranteed to play every week at champ / L1 level to learn on the job, like an apprenticeship, making mistakes along the way. Risk is that he doesn't get to experience the "higher level" skills & football intelligence.
Or go to a top prem club and learn from the experts, like at university. Risk is that he gets lazy and sits in their reserves for a few years drawing his £50k per week, but not playing.
He's at a junction and needs to make up his mind.