@KEV6934AI not building Tanks in TD, I did notice that, but there is a condition that causes it to happen.
IF 'Income' = 'LESS_THAN' 'Value_X' THEN Construct 'Unit_Harvester'
IF 'Income' = 'GREATER_THAN' 'Value_Y' AND IF 'Human_Player' owns Unit_Type = 'Unit_Tank' THEN Construct 'Unit_Tank'
This is based upon observations of matches I've played. When the Income is between 'Value_X' and 'Value_Y' then the AI will build its base as normal, but not build Tanks. This wasn't always the case, this is a new thing.