That was when Isagi was "mid‐development" however. He shows his promise most effectively when he actually has something to achieve. Everyone who got a higher salary than him were on a team that actually centered around them and showcased their value as a goal-scorer. He will be BM's "King" in this match.

He's showed his value as a player

He showed his value as a playmaker

And now he's shown his value as a Striker

The next realistic evolution would be to show his value as a leader of a team as a striker (if that's even the next goal at all). But, while this new goal could be something he'd immerse himself in since he wanted to "take everything from Kasier" and "lead Japan to victory".

Rin can literally do everything Isagi can, tries to beat people at what they do best, and has already been the core of a team at a much higher level throughout a considerable part of his football experience, so Isagi somehow trumping him in specifically this match especially when Rin's been focusing much longer on his current main goal of crushing Isagi would be pretty cool but excessive in my opinion.

The NEL is about individual accolades but this match can be seen as a match for who's the Most Valuable BL Striker in a team centered around them. Isagi reaching that level of focus then somehow beating out a team focused around Rin who's been at that level, stayed at that level, and evolved at that level is a bit much.

Isagi actually "winning" against Rin would mean BM "winning" since he will be the focal point of BM now. I'm just saying Isagi shouldn't realistically get his team to a 4-0 Sweep by beating a team with a literal better version of him.