Each controller is independent and the outputs will not be parallel unless you put them that way.
Connecting multiple solar panels to one charge controller.
Generally speaking it is a good idea to obtain your solar panels before you buy a charge controller.
Connect the negatives to the negatives and positives to the positives.
You can think of a charge controller in the same way that you would think of a hard drive on a computer.
If you connect the output of each controller on two separate battery banks each controller will charge the bank that is connected to its output using whatever power is available depending on the need state of charge the battery bank has.
Yes you can have two controllers on a one set of panels array.
For example our 115w sunpower solar blanket has the following ratings.
There is only a certain amount of data that a hard drive can store so you typically purchase a hard drive that is big enough for your needs.
Maximum rated voltage 19 8v.
Connecting two solar panels in parallel.
Maximum rated current 5 8a.