Give Arbalist - I personally see this as the Occam’s Razor. This doesn’t compromise their civ balance as being a heavily gold reliant civ and gives an answer to enemy Arbalests in the form of matching with your own, similar to matching against Goths infantry with your own. Naturally you will probably be up against better arbalists (vietnamese, ethiopian), but it’s better than lacking skirmishers AND arb, and it isn’t bad considering immediate bombard cannons. “But they already get Sipahi Cavalry Archers” This is a good argument and one that I initially rationalized for Turks not needing arbalist, however they are tied with Magyars for best cav archers in the game (As Magyars ca with full upgrades match the range of arbalists) and the function of arbalist over cav archer is completely different context in post-imp. Arbalists counter cav archers and even with the bulky extra HP turks get, it’s not realistic to fight them since arbalists are cheaper and have more range and more importantly, rate of fire. You never see Magyars making arbalists because their other options (specifically their cavalry) trade more than fine in niches where Turks would need arbalest. This keeps them reliant on gold without having such an obvious weakness.
Knights + 1 / 2 pierce armor per age - This is basically just a more flavored version of my Arbalist argument. Still rely on gold, but since they don’t get paladin (and it’d be funny if they did) this gives them a cost effecient trade for archer civs. Knights are still very expensive, and most civs going arbalest in post imp have halbs (ethiopians, vietnamese, incans, mayans, portuguese, britons) so it’s not like it locks civs out of a counter unit. Most cavalry civs (Persians, Berbers, Teutons, Franks, Lithuanians) wouldn’t struggle against it even if camels were on the field since their cavalry is either stronger or more cost effective, and either have access to halbs or camels; not to mention most cavalry civs aren’t making range units anyway outside of skirmishers and hand cannons.
No Changes - Ultimately, my arguments are on the basis of “IF Turks are to get buffed”
I still think they’re fine as is, but if I were to give them something, it’d be something like this. It’s true they struggle vs arbalest, but there’s a lot Turks can do before someone gets to mass arb. They’re an aggressive, gold reliant civ and should be played as such; you can’t sit in your base and boom with Turks, you have to raid and take map control, so I’m fine with them playing out this way and not having trash units. My problem with them as a civilization is that despite being the most gold reliant civ in the game, their options are fairly narrow compared to something like Portuguese. If they rely on gold, then they should have access to plenty of hard hitting gold power units. They do - cavalier, heavy camel, sipahi, and janissaries are all units that you could knock someone out with - but they don’t have as much flexiblity in their options such as a civ like Teutons, who can go for Paladins or Siege Onagers or Champion/Heavy scorp.
Additionally, there are things Turks can do against massed arb. They still have artillery bombard cannons, and as long as you protect them they can pot shot a ball of arbs all day. They still have free hussar and Cavalier, which take a while to mass to trade worthwhile vs arbs, but it’s still definitely possible.
As for other options, giving Onager same argument as Arbalest, and I don’t think Janissaries need to be buffed since they can trade effectively vs everything except siege, but free guilds would be nice since it saves the time and resources of having to research an absolutely necessary part of the Turks post-imp.