As detailed in this post where I beat a similar deck where the main difference was they had higher levels across the board (https://peakd.com/hive-13323/@badrag/reverse-speed-is-the-only-ruleset-that-actively-punishes-leveled-cards), reverse speed is the one ruleset that actively and almost universally punishes leveled cards (antithetical to the game’s ideals of requiring additional investment to succeed).
To address this, I don’t think removing the ruleset is ideal, as it is usually pretty fun. Instead, I’d make it so that speed increases as a card levels up are subtracted from it’s level 1 speed. So that leveling up would make the card better. This wouldn’t make all cards better, as cards starting at 1 speed couldn’t get faster. But it would mean that a leveled card was still always at least as good as its unleveled counterpart.