Two Outback80 connected

With multiple controllers (and possibly other DC connections, eg inverter), it's best to use buss bars for device connections, and a single +ive and -ive to the bank.  This avoids overcrowding the battery posts, which can cause problems.

The connections are otherwise much the same as shown in the manual for a single controller.  Outputs go to busses (with DC breaker on each +ive, breaker line terminal to battery if polarised). 

IIRC, only one temp sensor needed for multiple CCs.

I have Outback inverters, which pretty much requires a mate for settings.  The CCs have buttons and a small screen for setting up, but I'd still prefer to have a mate as it's more convenient to set and monitor. 

Syncing charge stages is nice to have, but maybe not essential, so you can probably get away without one.  Without sync, it just means one CC will go into float, with the other holding absorb voltage for a bit longer.  Not really that big of a deal IMHO. 

You'll want each to have its own temp sensor if no networking (mate and hub).  You might also want to look through the manual to make sure all the settings you need are available without the mate.  On my Classics, there are a few (non-essential) settings not in the unit menus but which can be set remotely.