Hi there.
I love this game, especially the Co-op gameplay. But I'm not that into the Mic-communication, personal stuff...
Therefore, so in my opinion, the ingame communication options like "Affarmative", "Need Backup" are not enough and lacking options for tactical play without mic.

For example:
Commander and Advisor could have commands such as "Stay there", "Guard this", "Spread out", "Get together" and so on...
For others, commands like "Moving / Going in", "Guarding this position", "Watch my back", "Nice work" ...

For the execution you could add a second choice-wheel on another keybind or add a second page to the existing one, switching with selecting page option or by scrolling with the mousewheel.

Yes, I'm aware that there is a chat option, but it costs time and people tend to ignore them, so voiced ingame commands are therefore better, faster and grant a better tactical feeling since there are audio and not chat based.

Those are just some thoughts, so feel free to add some in that direction.