No, Huns are basically Early Middle Ages, and the version of them that we have in game is more like their European integration, not stepparian nomads.
Turks already have Free Scout line Upgrades, they do not need Steppe lancers, and the Turks you have in game are the Sljuks and Ottomans, not the Turkmen tribes from Central Asia.
If you look from a historical point lots of civis should have them who used nomad mercenarys.China Mongol Hun Turks Bulgarians Lithuanians Slave maybe even magyars.
The Huns are NOT meant to be early European. They are meant to be Attila’s Huns, maybe the nomadic Avars, but with a really poor architecture set. If A nomad set was ever introduced they could be given that.
I say Persians should also get them alongside Huns and (maybe) Magyars. The Sasanid empire spanned from Middle East to Central Asia and overlapped with the steppe regions. Their armies also heavily consisted of cavalry and cavalry archers.
Paladin is already a huge investment upgrade (1300 Food, 750 Gold). Another upgrade on top of it would make it prohibitevely expensive, for such a minor stat boos as it would have to be for balance reasons (Paladin is already the strongest melee baseline unit in the game).
Frankly, Lancers on Mongols wasn’t even required. And I don’t think just making half the civs a SL civ is going to happen because they are supposed to be regional units like Eagles and Elephants.
The SL as it is right now needs all the help it can get. And no one is going to invest into them if they can’t ultimately upgrade them, and they will just go knight instead.
Steppe Lancers on Mongols at least has some flavour, since Mongols were the most famous stepparian people in History, and their Stables were not exactly great before the Steppe Lancer.
Huns, on the other hand, have FU Paladins, Hussars and Tarkans. Their UU makes sure they do not ever have to make Rams, since in groups, it brings buildings down fast.
Huns are one the best developed AoC civs, and do not ned any updates.
Persians have Longswordsmen because they are the Csatle Age upgrade to the most basic unit in the game, and the original devs did not want them to just have Militia or Men-at-Arms, as that would be very bad against Feudal rushes.