Bug in AI buys?

[snake]

Charles,
Well, the very next mission against GB was a meeting engagement and guess what? Yep, almost all Matilda II tanks again. That's now 4 in a row counting 1 French nothing but char bis buy.
In fact, the AI bought 35 Tanks. 3 A13, 4 Valentines and 28 Matilda II's. There were also 16 light varients plus cars and the usual 9 40mm, 8 25 pdr, 2 4.5" and 4 3" artillery sections. The rest of the 175 units was rifle sections - no transport.
So I'm not sure this rarity thing is working regardless of points available?! BTW my force value was 3960.

As a side note, I turned down art effectiveness to 10% while I wait for the patch to fix indirect fire top hits but it didn't make any difference that I can tell. The art falls near my armor - boom - armor gone. But at least I can do the same to him!