We all wait for our functional lives to end when Demigod adds voice chat, but even when it's in, it would still be beneficial to have a simple strategic interface in the HUD that lets you handle most team communication needs without speaking. This is a strategic, team game and it really has an opportunity to define what good built-in team UI looks like. The fact that it could serve as a management tool for the AI bots is a bonus.
I'm picturing three additions to the demigod UI: a team status box, a simple chat interface and a change to the citadel buying screen.
The status box sits open permanently in the lower left and shows you the team, demigod, name, level, and last known health/possible health of every player in the game. For allies, that's always the latest info. For enemies, that's the latest known info, or latest witnessed by a member of your team. Or whatever. You can target spells by clicking the teammate's or opponent's name in the status box. This is the healing interface that makes Oak, Sedna and QoT much better support players.
The chat interface would be really minimal, like counterstrike, you'd have a couple status messages (Run, Heal me, Help needed, OOM, need help left/center/right, focus on this enemy) that are one or two clicks away, and the messages would display in the status box and ping on the minimap.
Finally, every option on the citadel buying screen would have two right click choices, so players could set one of two flags on an item: "let's get this", a request for someone on the team to buy an upgrade or "I'll buy this", stating a promise to buy it yourself. Each player can set one of each type of flag. These requests or promises are visible to all players on the team in the status box and whenever they open the citadel screen.
This simple communication framework would make a lot of strategic decisions and planning easier for teams without voice chat and allow for clear, intentional planning for teams that don't speak the same language or that have AI bots on their side.