Okay, lets continue with the number of AIO servers. The reason you have 40 of them is because maxservers is applied on a per CPU bases. If maxservers = 10 and you have 4 CPUs, then you'll have 40 AIO servers.
I take it from your post that you don't know what the volume of your async I/O is but, since you're runiing Oracle, async I/O is important to good performance.
The rule of thumb is to set maxservers to the number of disks access async - in other words, the number of disks used by Oracle, multiplied by 10.
Lets assume you have an Oracle volume group with six physical disks assigned to it - regardless of whether mirrored or not. You would want to set maxservers=60.
Now you decide to create a RAID 5 array from your storage device w/ 14 data disks, 1 parity disk and 1 hot spare. You create 4 LUNs.
Your
AIX server now has 4 new hdisks. How many AIOs do you add: 40, 140 or 150?
The answer is 140, 10 times the number of physical devices you're adding. So maxservers = 180.
And how many AIO servers should you actually have active on your system? 4 * 180, or 640 AIO servers.
Remember, this only matters if your Oracle database is filesystem based. If your database resides on raw logical volumes, then AIO offers you very little benefit.