I think the general idea behind T3 balance is actually, to have people being able to buy into the game, just before the endgame starts, without imbalancing the endgame. Which kinda starts mid T4 atm.
Ships like the Sai and the DEagle also play a role in the gameplay, by filling obvious holes, which are not present in T4. Mostly because golden ships have R9 slots, also ships like the Nukem or Eagle-B replace some R7 ships. Tier 3 after all starts with 3 actives, but ends with 4, so the tier is divided itself, being the golden center of players. I don’t say all of those ships do have a role, like the Reaper, but especially the Sai being the only decent alternative to a Swarm does.
The Upside of this is, that you cannot call the game pay2win, while still retaining the kind of somewhat “unique” feel somebody wants with a DLC ship.
Having those ships being upgradable to higher tiers would be nice; however e.g. there are fed recons in T4 capable of competing with the Sai in every regard.
And the flipside of T4 DLC ships is, that their stats would be somewhere between T4 and T5, as are most DLC ships between T3 and T4, because from a product standpoint, you have to have some legitimation, why you want somebody to pay a bigger amount in microtransactionland. I mean, these ships are expensive as they are, and they have their main spotlight in the most general tier there is.
Certain players dislike T3 at this moment already, because they think premium ships is all you need to compete. T3 is usually heavily filled with payed ships, also since we love to stack up free synergy in that tier. So I am not sure, how it would be, if suddenly T5 endgame would end up with DLC ships flying around.
Don’t get me wrong, I personally am neither opposed or attracted to this proposition.
The funny thing about the game is… that when you beat the enemy player with a squad of premium ships with purple gear, they always think that’s the only reason they lost - because you had advantage of more powerful gear.
It may be true that their non-maxed ships with mk2 gear might be quite a disadvantage at a point, but that still isn’t the main reason. However, they will always think (and blame you) that it’s the better gear and is not a fair fight. Because it’s easier to accept that someone has better gear than their own ability. Keeping it this way, it gives you reason to progress and play the game (=income) to earn those purples . But by the time you get them, you will also improve your skills by equal (or higher) margin, making you think that the gear helps you, and that it did to others before you…
The only thing that really matters is being energy stable, which you reach at near-max sinergy levels, so a lot of ships are crap from the start that are not stable yet, because this can give you some real trouble like not being able to afterburn or activate your modules in dire need. But once you get there the rest of the stats don’t have a noticable impact that you can feel. We are talking of improvements of 3-5% that purple gear gives over the green one. Nobody really believes that 5% better stats give you a total edge over the oponent, it’s not even close to that. The only thing that some premium ships do have going for is better module layout on some models and passive buffs of questionable balance (that got nerfed many times anyway). The Sai, in particular, is still far superior and too good compared to the rest of the recon line; that one needs some kind of improvement. But apart from that, prem ships are generally just great tool to farm free sinergy in the long run and are thus good to have, because you never have enough of that, and T3 being the most populated tier, it’s a good investment.