Azir is a better version of Heimerdinger
Sadly, that is what i feel. they are both mages that excel on controlling zones and map.
Azir has soldiers, Himer has turrets
Soldiers move and you can dash with them, Heimer cannot
Azir can replace soldiers and move them freely, Heimer cannot
Azir can dahs and get shield, Heimer cannot
Azir can block an entire passage with his R, Himer cannot (he can at best stun multiple target with ulti+E)
Azir can do crazy combo when he pull back enemies into the team, Heimer cannot
I just feel thata they do similar things but azir do it better, considering the amount of damage that those soldiers can put up i would just say thet he is better.
Not that i hate Heimer, but he need some love, Yes he can do crazy damage too but you need time to set up the turrets, then have 1 turret ready for the teamfight to put the Big One down and even then you have no chance to survive if they pile on you.
Azir has more tools but fills a similar role, means something is wrong.
does have his soldier's, they only last for a very short amount of time, you just have to play around the CD window.
on the other hand, places 3 turrets that DON'T have a time limit, and can save some in reserve for when they DO get killed.