The two connecting rooms at POR in AB would give you 4 real beds and 2 small beds that fold down from an armoire ( one in each room). Requesting connecting rooms is a request for an interior door between the two rooms. Adjoining rooms are rooms that share a wall but you have to exit one room to the outside and then enter the other through its entrance.
You will be given priority for being granted your request (as a family with small children), and odds are good if you make it your only request. However, it does happen that families with children do NOT get connecting rooms - despite any 'guarantees' that you may be offered either verbally or in writing. Disney views it as possible as one parent is expected to stay in each room with some of the children. Not ideal, and it is the risk that you take. The appeal of AoA is that you will all be definitely in the same living space.
Preferred rooms are in AB and in a limited number of two storey buildings that are conveniently located near the themed pool, food court, activities, etc. another option would be the pool view Royal Rooms. These are more expensive and do not have trundle beds, but they are almost all in the Oak Manor building all along one side facing the pool. Both preferred rooms and Royal Rooms are more expensive than the standard rooms and are bookable categories.
If you go to the website portorleans.org you will be able to look at maps of the rooms at the resort and see where they are located. That may help you decide which would work better for your family.
We prefer to book two rooms in most situations because we all like real beds to sleep in and we generally fine as long as we are in the same resort. We request connecting rooms every time we do this and sometimes we get them, sometimes we don't. If you do arrive to rooms that are not together, you may be able to get them moved, if not right away, often by the next day.
FYI: Other options are available, such as and All Star Music suite, cabins at FW or a deluxe room (sleeps 6) at WL or BWI, for example.
Good luck!