They are supposed to be long ranged support, not close ranged blap all.

I see railgun tanks killing infantry more easily than my missile turret can. Facing armor railgun tanks brings my shield to low levels while shield railgun tanks just pop me effortlessly.

The railgun is horribly broken and OP, even at the militia level. First of all, it makes zero sense that a non-explosive kinetic slug has a larger splash radius and higher splash damage than an explosive missile. It's like trying to say that if a .50 cal sniper rifle hits the ground next to your foot, it should blow your foot clean off. All that it should do is kick up some dirt and give you some scratches at worst.

Second, as I already mentioned, it beats the missile turret in vehicle combat. Not only is it accurate at long range, but it doesn't care what vehicle it's fighting, while the missile launcher is only good up to medium range and cares about which vehicle it's fighting.

The missile launcher should be the tankbuster, not the railgun. Making the tankbuster a long ranged weapon such as the railgun is horribly broken.

I say, if the railgun wants it's range, then increase heat cost per shot to 40 and reduce damage by 100-200. It should overheat fast, discouraging its use in close range while keeping it suitable at long range. These two changes will force railgunners out at long ranges to provide support fire, as they will be bested by missile turrets, no matter if they are shield or armor.

However, if they want to keep their utility (which every scrub militia rail tanker would want), I say bring the splash radius back on missiles (at least 3m, but I think 4m should be a good starting point) and increase the clip size to 14 on large missile launchers (I count 7 missile tubes on each side on the turret model). These two changes will make the missile turret more competitive against the oh so popular railgun.