No. Stop this. This is so incredibly dumb. Don’t try to bring “real life” into EVE Online.
It’s something called “Balance”. Welcome to video games?
Why should Vagabonds and Sleipnirs both be made to be equally cap stable with the exact same fit? You’re making the (horrifically mistaken) assumption that the Slep the same as a Vagabond, just ‘bigger’. That’s not how these ships work, and expecting them to work that was is incredibly silly.