As someone on the team of a mod (Legion) that freely mixes FS1 and FS2 assets...
FS1's balance is ****. Absolute, unmitigated, Clostridium difficile-infected fecal matter. The difference in power between the ML-16 and other weapons is absurd, the intended progression curve of the other primary weapons is essentially inverted (the Banshee is worse than the Prometheus, which is worse than the Avenger), the Anubis could have been a viable fighter if it had an afterburner (what the ****, Volition?), the observed behavior of weapons and ships frequently contradict their in-universe description and role, the list goes on and on and on.
I can't rebalance the FS1 stuff for this campaign, but god damn do I ever want to. FreeSpace 1 is an ungodly mess of a game and I encourage anyone else developing a campaign set before FS2 to chuck the table values from FS1 in the garbage and rebalance based on FS2 or just from scratch. FS2 was a rushed product with less than a year of development yet its gameplay balance wipes the floor with FS1's (not that it's perfect, it's just better by far).