Hello!

For most players, they do always pick the element that gives a power boost for their P1 ninja. In your case, if you're going for Minato Namikaze [Edo Tensei], you might want to choose and upgrade your Temari Card first. Or you may also choose to upgrade the Tenten Card for the Critical Bonus that will be in effect for your whole team. In my opinion, it is better if you will choose and upgrade the Kage Cards first (For most ninja element that you have that you think is usable for main battles) and follow-up the Kage's Assistants Cards, that's what I did before.

Hope my response gave you an idea even for a bit and helped you with your inquiry. Thank you.