After all, all views are subjective. Whilst some of us might not fancy the Thunder, it might work great for others.
Just to be clear, the way I score a fighter's usefulness is by 1) survivability (if I need to replace the whole wing 3 times in the 1st 15 seconds of a fight, that fighter is crap), which almost always means a shield or a phase cloak 2) firepower (how quick can he take down his intended target, may he be specialised against smaller or bigger ships) and 3) support (it's a PD boat ? it's a distraction ? it's a meat wagon ?).
Also, to be perfectly honest, the Templars have no point in this categorisation. Mainly because they are a very powerful faction. You could just make that Tier 0 and put all of them there. I doubt there's any ship in this game that can compete toe-to-toe with the same class Templar ship. Nevermind the Paladin that can take down whole armadas by itself.
Again, I LOVE this faction. It's probably one of the most interesting, well built factions. With special skills, amazing ships and that higher difficulty. It's perfect for the campaign (and I have it in every single campaign I play, no questions asked), as end-game content. But in this classification .. perhaps not.