If I am seeing this correctly, they are both identical DPS, on hull and shield the only difference is the range, projectile speed, refire rate and energy useage. Please correct me if I am wrong but this seems a little odd.
It is damage per shot, not damage per second. Mortar damage per second is 56K, while the Razor's is 28K. Furthermore, the razor uses much more energy for 1 unit of damage than the mortar, which makes it less efficient. The infocards are correct, but this doesn't mean that the Razor is as damaging as the Mortar in the long run. Only per 1 shot. If you scoured through update history, you'd find that the Razor damage per shot was increased from 140K to 280K, and the range reduced from 1.6K to 1.3K.