そうすれば、 シュートではチームーの選手ではなくてもチームのためには欠くことのできない存在となれるでしょう。
I think the ではなくても part plays a big role in defining the condition of this statement.
By that conditional alone, this indicates 'even if not the best player' regarding 'Shoot' would also mean 'in that situation, even if Shoot is not the best team player for the team, that person's existence on the team is indispensable.'
To me, this tells me, due to the article being mentioned, the last part indicates 'it seems indispensable existence becomes' to be more Japanese grammar literal.
Toritoribe mentioned では is a rough comparison from the player to Shoot.
Putting this into an English perspective:
In that situation, even if Shoot is not the best team player on the team, it seems they become indispensable.
The major problem becomes となれる.
This indicates the preceding phrase 'becomes seemingly indispensable.'
If I have this right:
"If they do that, even if Shoot is not the best player for the team's advantage, I think it amounts to becoming indispensable."
I'm not sure if I got this right, but I did spend a lot of time thinking about the grammar and functions.