Okay Riot, question time.
Why does Azir have a secondary that says marksman and why does TwistedFate not have it?
Azir's kit has nothing to do with AD. Which means, you need to debuff (nerf) some of those skills and bring in some AD. If not, then he's just a mage. Because I have no reason to get a 
for someone who needs a stupid 
and 
to use his abilities correctly. There's no room and no reason. You can most definitely give his W (and/or Q) AD. Give him a reason to get some AD like, for you gain a bonus 0.1 seconds for your turrent for every bonus 10/15/20 AD scaling from 1/7/13. And none of his abilities are applicable for spell vamp. So 
and 
are out of the question.
On the other hand, TwistedFate can use both so easily. His Q is already strong and useful with out AD. His W scales with full AD and some AP. His E gives him AS and gives a nice bonus damage. And his kit is applicable for all the above.
If you are to make Azir a part marksman, you really need to think on it. None of his kit really allows it except for his passives passive. What I think should be done is:
- Make his Q and E available with and without his soldiers. Give the Q a shot type of action where he shoots a sand rod out and hits the first enemy or monster. His E can just give him a shield for crying out loud. If there is a enemy, he can do the maneuver to do some damage.
The guy would be fun as a marksman but his kit is just to much like a mage. It'd be easier to play a Sona or Vel'Koz as a marksman than it would for Azir.
and 
. All of these champs can use AP yet they are also marksmen. Sure, Ezreal, Corki, Kog,Maw, and Twitch can use AD but they still have AP as well. Kennen, Teemo, and Tristana have made APC a thing. But they are still able to use 
and 
can never (truly) ADC or APC.