A weird Bug

Not sure which exact forum but this weird occurrence has been happening to me.

I have been able to recreate a strange occurrence and was wondering if anyone else would be able to or explain why it is occurring.

During a long thread battle back to back on private challenges I found myself against a Spammy outcast frigate battle.

I figured the exact proportion of rocket fighters needed to destroy them (approx 1/3). I did this multiple times so as not to have a fluke.

Then I added a cruiser mix. And lost.

The fighters by themselves would wipe out the frigates.
The fighters with cruisers on the map but not engaged would lose, with about 70% of the frigates still alive,

This occurred with other races.
Fighters by themselves would win
Add cruisers (that would not engage) and the fighters would by destroyed, still leaving 70% or so of the frigates alive.

I am pondering what would cause the fighters to suddenly become so terrible?

Also posted to the Steam Community