It's not a "downgrade". The fact that you even say that shows how much you room you have to grow in this game. The Viper 3 and the Eagle II are both extremely powerful ships in the right hands. Somewhat hard fir the AI to counter in larger slower ships.
Also very cheap ships to learn the actual combat mechanics. If you still don't want to learn them though, you can just regrind to partial Engi mods and do even better than 2.0 vs NPCs.
So there is something for everyone in 2.1. Skilled pilots can just take advantage of it immediately. Less skilled can either fly small ships, or earn the ability to fight master and above AI (based on pure ship stats, sans skill) by hunting mats.
Btw, I am only a semi-skilled pilot, not amazing at all. So I am jumping in an iEagle to gather my mats to reboost my FDL back into an undisputed killing machine.
It is a downgrade. An Eagle dies if you spit at it, and its power juggling issues are even WORSE than the Vulture. It's also considerably slower for not being much more maneuverable. The iEagle is better in this regard, but its still inferior in almost every way to the Vulture. And the only thing a Viper III has on a Vulture is pure speed.
And the FDL is way deadlier than all four ships here.
In both speed and maneuverability, the Clipper beats them all except for the two Core Dynamics ships, which can out turn it. But the Clipper's ludicrous speed and general firepower trivialize their advantages; the Vulture can beat it, but you're still in the situation where better ships are still better.
Going to lower ships is still downgrading, and you also leave out that every ship has its own quirk; learning to fly in one ship doesn't necessarily translate to the same in another ship.
The one upside to getting into these lower cost ships is that they are low cost and low maintenance.
About as long as modern "L2P/Get Gud" gamers would last if they snarked off in the Tudor Court on which that stuff is based. (WHACK!.....thunk)
ASOIAF is based on the War of the Roses. So, the Yorks and the Lancasters. The Tudors came later.