Keep in mind that when hitting a strategic target other than the HQ, a formation of Ki-67s dropping twenty-four 100kg bombs does almost as much damage as a formation of Lancasters dropping fourty-two 1,000lb bombs or three 4,000lbs bombs fifty-four 500lbs bombs.
Therefore the Ki-67 is, overall, much more effective against cities and factories than is the Lancaster because it climbs more than twice as fast, flies at a higher speed, is better defended and does nearly as much damage.
Payload doesn't mean all that much. The ability to distribute it does. That is why the Ki-67 is a better bomber than the P-38L in AH, despite the lower payload.