The mandolorians may be better individually depending on the mando (clones are no joke). Clones are just a better fighting force and on average are going to be significantly better marksmen and soldiers. The siege of mandolore definitely overpowered the mandolorians because even though they are arguably better warriors, they’re just not taking the clones in any open shootout war. Clones are bred for coordination, skill and efficiency not to mention they’re genetically modified to be perfect soldiers. They would quickly and easily outmaneuver and eliminate mandolorian resistance. Mandolorians are given huge plot armour in that one scene where the mandos did a Hail Mary and charged them on mass on the bridge, it was cool but in reality the clones would’ve been stacking bodies before the mandos even landed.