Kaucukovnik: You can use a generic Large Address Aware patch on the executable to make any 32-bit version able to access all your memory.
Wow I got a reply. Would have been nice if GoG notified me about this.
Thanks but the problem isn't strictly related to LAA it's due to the persistent memory leak in the 32-bit version. 4gb patch was the first thing I tried.
I've tried all 3 versions of this game extensively. HE was the only version that was completely stable both vanilla and modded.
The issue likely won't be evident unless you play huge maps against several hard AI.