Agree with all of this. Summerville in isolation is a decent player and he's a different profile to the wide options we already have.
But he's also a blocker to future signings.
If you buy Summerville - add him to a newly signed Cunha & Mbeumo, as well as Amad who has a contract until 2030 - you're almost committing to that being your crop of wide players for the next few seasons.
And I don't feel that quartet is quite good enough to challenge for trophies. It lacks a genuine superstar, or potential superstar, level talent.
I know it seems like a pipe dream when we can't even beat Spurs to signings, and it'll probably remain one, but Vini Jr's contract expires in 2027. Maybe he'd fancy a Premier League move, maybe he has Wayne Rooney pyjamas? That's the type of signing that can make a team jump a level. It's also the type of signing that makes the club more attractive and an easier sell to other talents.
Barcola expires in 2028. A transfer next summer for him is very realistic.