Cronus 3M has a Large Laser which is backed up by three Medium Lasers and a SRM-4 launcher
Cronus 5M has ER PPC, 2 ER Medium Lasers, ER Small Laser and a Streak SRM-4 Launcher
Thunderbolt 5S has Large Laser, LRM-15 Launcher, 3 Medium Lasers, SRM-2 and pair of Machine Guns
Thunderbolt 5Sb has ER PPC, LRM-15 + Art, 3 Medium Lasers, Streak SRM 2 and pair Small Lasers.
This is just sample comparison.
Aside from the LRM launcher, slight bigger SRM Launcher, 3M resembles Thunderbolt 5S in weapons load out.
While the 5M resembles the Star League Royal variant, 5Sb, again minus the LRM launcher, one less Smaller Laser (be it order tech one)
My point is, they have also a similar weapons load out as well.
Anyways, Cronus trough cookie for it's time. Frankly i enjoy them.
Thunderbolt has similar variants armed accordingly .