What you're doing wrong, very honestly, is you suggest and 2 of your suggestions are losses (denying release).
Dont suggest, make enemies: send emails to both teams saying now it must be like that, lay the plan, pose a meeting to go through the plan and get yelled at. Once you get yelled at by the complainypants because what you tell them to do is too hard, now you can go to your manager and explain him they complain for the sake of complaining. The tech lead will get a earful and either fight you to his grave or admit defeat and let you do your reform grumbling waiting for you to fail.
I do that in a giant bank that cannot move without 10 approvers to everything, and the more these helpless teams fight me the more management put me in their midst to reform them ... and Im just a silly dev nobody and I can tell you the wonders one can do by just bulldozing. There are things to do if you fail eventually, which is to teach the higher ups to enjoy trying and failing, but that requires a bit of weaseling charisma :D
It's a fun game to play, until you realize it's not your job to manage the managers and your co-workers, and that you're underpaid for having that extra headache :)
Dont suggest, make enemies: send emails to both teams saying now it must be like that, lay the plan, pose a meeting to go through the plan and get yelled at. Once you get yelled at by the complainypants because what you tell them to do is too hard, now you can go to your manager and explain him they complain for the sake of complaining. The tech lead will get a earful and either fight you to his grave or admit defeat and let you do your reform grumbling waiting for you to fail.
I do that in a giant bank that cannot move without 10 approvers to everything, and the more these helpless teams fight me the more management put me in their midst to reform them ... and Im just a silly dev nobody and I can tell you the wonders one can do by just bulldozing. There are things to do if you fail eventually, which is to teach the higher ups to enjoy trying and failing, but that requires a bit of weaseling charisma :D