Welcome to the forum.
Did BB recommend you get 2 of those chargers for your 4 batteries?
Are these 4 12V in parallel?
You can have two dozen chargers connected to the same bank as long as the chargers are programmed to the correct settings. As long as the batteries are able to receive > 80A under the absorption voltage, then you will get current from both chargers. Once absorption voltage is hit, the current gets tapered to hold that voltage. Once the total current needed to hold the absorption drops below 80A, one of the chargers will drop to float voltage.
You should definitely connect as you describe, (+) on 1 and (-) on 4. It's optional how you connect the second either same or opposite as the first. I have no data to support the preference, but I imagine the second with (+) on 4 and (-) on 1 might improve uniformity of charging.
Given the current you're pushing, you need BEEFY and short cables between the chargers and the battery bank. If you use thin wire or have a long run, you may lose a large portion of the available current due to voltage drop.