What made WarThunder so popular is that they implemented
three different mouse control modes in their game:
1) Relative mouse control - a standard way where you have to constantly move the mouse during a turn.
2) Virtual joystick. Using your mouse you put virtual stick into position you need to perform turn. The position of your virtual joystick is displayed on a screen as a white dot that moves around gunsite area. The central (neutral) position of virtual joystick is a center of gunsite.
This type of control seems to be clumsy from the first look and has received lots of criticism in the past until some guys discovered the best sensitivity settings for this setup and started to show quite impressive results with it.
In this video
russian player using this control mode flies Yak in between vertical frames of the bridge (90 degree roll) 1:20 and under the bridge inverted 2:30 . In the end of the video when he was flying P47 and shot down several players in SB arena he was called a cheater

3) Mouse Aim. It is actually mouse over AI control mode. You click on the screen giving direction to AI (that actually controls the plane) and AI performs the rest/best to bring your plane to this point. The most easy way to operate the plane. Some people call it the noob-catering casual retard control. With F3 view mode it is quite effective and brings lots of new customers to the game on every day basis.
For HTC the first goal if they really want to bring many new customers into the game is to create similar mouse control modes to bring as many free-to play customers into the game as possible.(I would recommend creating WarThunder setup profile to map the most important controls/keys the way they mapped in Warthunder by default).
The next goal should be to motivate these customers to upgrade their hardware (get real Joysticks etc) and become a subscribers. This part is much more difficult and for example WarThunder (to tell the story short) actually failed to create environment in their SB/RB arenas to motivate people to migrate massively to these arenas from arcade battles. Otherwise they would have already doubled/tripled their revenue.
Actually AH has much more potential in achieving this goal as everybody will be playing in one arena and it will be obvious that people who play with joysticks have advantage.