Is that they are designed for Massive infantry rushes....... something that rarely happens in planetside 2.(which is ironic..... probally because HE) Now Since HE can be equipted by anyone with a Tank the Mass damage amount in big fights can get crazy. HE was originally designed for Field battles.(which is why it has the radius it does) So.... What happens when you shoot a Round that was designed for AI area control into a small structure? Certs(and dead bodies) pile up. the problem with HE is that It really shouldn't be on the MBT's. HEAT rounds already fill that role, by being Decent vs all targets, and having better splash then AP rounds(which are designed to deal with Armored targets/base defenses). HE just feels un-needed on the MBT, While on the lightning HE rounds work well. But you could Take the creative approach and remove HE rounds from all tanks and instead put it on a separate Tank entirely. Such as a Empire Specific Battle Tank, Battle tanks would be the middle ground between lightnings and MBT's(interms of HP, speed, and armor). But they would only be able to use HE rounds. This would leave MBT's as HEAT and AP users, making them more of a MBT. This would leave lightnings with Skyguards,Vipers, AP, and HEAT rounds.... making them versatile Tanks. BT's would just have HE rounds, meaning They wouldn't do well against other tanks, but they would do well suppressing infantry, however since they would be more fragile then the MBT's yet slower and more armored then lightening's it would have its place in a diverse battlefield.