Sides A (north) and B (south) are really only important for where to go for ticket counters and baggage claim, which of course won't matter to you when connecting (you can walk between the two sides if you're landside; it's basically reminiscent of a shopping mall in between). More important for connections is that gates 1-59 are connected airside (west), as are 70-129 (east) - but you must connect landside if one gate is numbered below 70 and the other above. Even with that you may have to take the train to the terminal - don't leave airside - and another one back out to the other "pod" even if you are transiting between two gates that are connected airside. I believe AS is in "pod" Airside 2, which if so means your AA flight has to be between gates 70-129 to make an airside connection (per Wikipedia, for whatever that's worth, AA uses gates 30-59).

MCO is an annoying airport to connect through, probably because the vast majority of pax are O&D. Even on American I've had to leave airside to connect between two flights due to the gates they were at (possibly because it was domestic to international).

Sorry that's so confusing!