because translating the rules straight from TT doest work well in this type of videogame.
it may very well work if all the weapons only fired once every 10 seconds per TT, but being able to shoot your laser 3 times in 10 seconds and having it do full damage with no threat of overheat is not optimal.
They need to revisit the 10 second rule then and figure out how to appropriately normalize damage across this range with w/e cycle times they choose. ALL the balance problems currently stem from this. I promise you small lasers wouldn't be so popular if they dumped their damage in the same time as medium and large lasers.
I can make this really simple for them:
Lasers: 2 second firing, 3 second cooldown. Half heat and damage of TT values.
Pulse Lasers: 1 second firing in 2 pulses. 1/3 heat and damage of TT values.
AC20: 8 second cooldown. 20% less heat and damage from TT, 20% more ammo.
AC10: 6 second cooldown. 40% less heat and damage from TT, 40% more ammo.
AC5: 4 second cooldown. 60% less heat and damage from TT, 60% more ammo.
AC2: 2 second cooldown. 80% less heat and damage from TT, 80% more ammo.
See where I'm going with this? It really isn't that hard to establish a good, logical starting point, and make your balance changes from there.