Ahh. Excellent tip.
One thing though - I've not found it necessary to split the main potions - when 'paired' as a team, whosever potion Icon you click on gives access to all potions owned by both members.
What does bug me though is that, unlike DD, you don't have access to the other potions (eg Strength, speed etc) without opening the inventory first. Unless I've missed something. (Wouldn't surprise me...)