It is very common practice to have more than one attorney listed on an PoA to act on your behalf in case something happens. Banks will be able to accommodate this when registering multiple attorneys in the event that the donor loses mental capacity.
How you make decisions will depend on the powers you are granted on your PoA document. If all attorneys are listed as 'jointly', then all must agree when making decisions on behalf of the donor.
If listed as 'jointly or separately' this means that all attorneys have the right to make decisions on the donor's behalf without the need for unanimous decision-making.
Often if there are multiple attorneys who must make decisions 'jointly', you will all have to attend a branch appointment to manage the donor's finances.