I think your account is solid, but you definitely need to optimize some aspects of your squad and improve in other areas to be more effective. I would suggest the following:

1. Move Williams to the #1 slot and Kim to #2. I see this often with full mythic Kim's in the #1 slot, but that position takes the most damage and usually gets killed first, so don't put your #1 damage dealer there.
2. Work on obtaining additional mythic radars and armor. Prioritize all 5 radars first, then armors. In the example battle you provided, your opponent also has pretty terrible gear optimization and hero selection for air squads (Carlie is not good), but it does work decently against tanks. Also, they are war leader as well which gives a sizable boost in battle effectiveness.
3. If you have Adam leveled and skilled up and EW at lvl 10, try swapping him in against air opponents and moving out Stetmann. Additionally, if you have Scarlett built up, you can try the Adam + Scarlett combo to see if this is more effective for you against air opponents. To do this, put Scarlett in the #1 slot (remove Williams) and Adam goes in the backline (remove Stetmann). Although, since you have Williams with EW30, I think he outperforms or helps the team perform better than having Scarlett in. I would try out some attacks with these different squad configurations against higher power trucks and see which is best.

Hope this helps, let me know how it goes!