Never use them, because they're part of the fluff, not part of the stats.
The evolution of the race in question is measured by movement on the PL scale, Armageddon is proof of that. Never mind that because of the little vs. large issue, the EA seem to be evolving backwards in terms of combat efficiency.
Actual advancement is getting better ships for the same PL, like Marathon over Omega- but where's it's support? The Centauri were doing well out of that, until the Liati came along (I'm sorry if I reminded anyone who had successfully airbrushed it out of their minds about that flying s*x-t&y of a ship).
On Primus vs. Tertius; against some opponents- Drazi, EA- two flights of Razik can actually go quite a long way to keep your ships in one piece. They do keep the T- bolts and Sky Serpents off.