Mixed Up Mod Percentages

I have a c7 level "6" anti-melee servo at +34.44% damage and another c7 level "5" anti-melee servo at +37.92%.

Why is the level 5 mod higher % than the level 6 mod?

The level 6 mod is on a fully upgraded totem and the level 5 mod is on a fully upgraded medallion. Does that make a difference? Is this a common occurrence?  

If you hold Alt while looking at your relic does the mod have Vii next to it? if not you have a lower chaos mod on a higher chaos relic