Many years ago, fans of Glorantha had an attitude that D20 games wouldn’t fit in Glorantha, as Classes and Levels don’t work. Then came 13th Age Glorantha to disprove that notion. Also, many people in the D100 space looked down on D20 games as Classes and Levels don’t work with D100. Then came Classic Fantasy to disprove that notion.
I once mentioned the idea of converting 13th Age Glorantha so that it would work with D100, but the idea was unpopular, as it was considered Crossing the Strea