Yep. I was originally commissioned as an Armor officer back in '91. The Armor Officer Basic course was 4-5 months long, and that was to teach lieutenants how to maintain and fight an Abrams platoon as well as some other basic core stuff that wasn't specifically related to tank warfare (i.e. M9 pistol qualification, UCMJ, etc.)
Of course, even after that 4-5 month course, it was assumed the graduate would be going to an active unit for continued OJT, with an established organizational level motor pool and a direct support shop for higher level maintenance.
31 tanks is a battalion by old soviet organizational doctrine. Not sure about now, but when I was in, a US Armor battalion had 58 tanks (4 companies with 14 tanks, and two tanks in the battalion HQ for the commander and S3). The soviet line battalions had IIRC, 3 companies of 10 + the battalion commander for 31.
That probably explains the odd number 31?