Some support gems not stacking with the Gemling Gem Studded node.

Hello I have A Gemling Legionnaire with the Gem Studded node that lets you use two copies of support gems. I also have the Overwhelming Presence and Attrition aura skills. I tired putting the Vitality and Clarity support gems that increase health regen and mana regen into both skills. Just one of each gem in each skill. I didn't double up. They do not appear to stack though. Let me know if you need any more info. Thanks.