In my opinion King tiger shouldn't be able to be built unless all three trucks are built and alive. That way You can't throw away a flak HQ and bank on a King tiger.
Btw, i've seen KT in around 20min in 2vs2 which is no way balanced. OKW needed a buff, but no need of a number of CP's for a heavy tank (like the others do) is a huge mistake. Everybody could see that except relic and axisfanboys.
Problem with KT now is timing. Just add a marker with 13cps(or lower) after you build or tiers like other heavies and problem solved. But that won't stop the rush of okw tanks which is also a huge problem.