I don't know if this will help but in CMBO, when I wanted a tank to go hull down, I aimed for the crest of hill with a hunt order. When an enemy tank would appear in LOS my tank would stop right on top of the crest and be hull down. When I try the same thing in CMBB a tank usually gets LOS and stops a few meters below the crest. So compared to CMBO it seems that CMBB tanks aquire LOS a bit faster and try to engage in a too deep hull down position.