Siege tank is could use a little buff, since it's not "punchy" enough for it's build time & price.
- Better aim assist for the arc projectile. as an artillery unit it should be able to shoot behind cover, not just line of sight. (the picture is an example of a way to show how the projectile will arc and fall.)
- Being able to switch between an arc artillery shot with full damage, and a straight flying- shot with damage drop-off, so it can still counter collosi.