If you are appointing more than 1 person to act as your Donees, they can be appointed jointly or jointly and severally. There are pros and cons in either mode.
If they are appointed jointly, all of them will need to act unanimously at all times, eg. all signing cheques. This may cause administrative difficulties if one of them is away on holiday. If one of them die or become a bankrupt, or mentally incapacitated, your Lasting Power of Attorney may be invalidated.
If you appoint Donees to act jointly and severally, this will mean that any one of them will be able to act on his own and should any of them dies or becomes bankrupt, the remaining Donee will be able to continue to act.
Usually, it is a matter of trust that the Donor places on each Donee to act in his or her best interest. If the Donor is comfortable with any Donee making decisions on his or her behalf, then he or she should select the mode “jointly and severally”.
It is ultimately a matter of choice for the Donor to decide.