Any advice for having co-agents named in POA?

A person really has to have a very clear understanding of their family dynamics and how they may play out. Lots of people will tell you it is important to have one primary POA with others named as back ups so that if there is ever any disagreement there is a clear decision maker. People will tell you it is also important to have the same person as both financial and medical POA so that when the two roles overlap , such as when decisions need to be made about hiring caregivers or choosing long term care, there is no conflict.
On the other hand granting complete authority to only one can leave you open to abuse, since no other family or friends will have any ability to oversee or opine about finances or care plans. Many families have successfully named multiple agents in both capacities jointly and severally (either/or) and it can work very well, allowing those named to share the burden.

I think it’s a good idea to have one POA as primary and at least one more secondary. If the principal has dementia you want to keep this updated while they can still make changes.
My parents had all four of their children as POA for both medical and financial. I was the only one who acted on it. We worked very well together. No problems.
My in laws had oldest first, next oldest second and so forth.
My aunt has me as primary and a nephew secondary. That nephew died, so we changed it to another.
I’m actually thinking of adding a third now because of our ages. Have been talking to aunt about adding a great niece who helps me with aunts care. It’s important to get it done. You can always change it as long as principal is capable.
Unless you make it where each can act independent co makes both have to be present. Not always possible for me. And what if one of the two couldn’t act, died? That has to be thought out. If document said both had to sign and only one there would be like not having a POA at all.