You NEED to give players an option to use UNIT TYPE TAB CYCLING instead of individual unit tab cycling. Never have I had such a difficult time controlling units in a large-scale / high-supply cap RTS – you're making it DIFFICULT for players to control their units.
In Dawn of War III, if I have a control group consisting of Gorgutz, 3 Nobz and 6 Boyz, I have to press tab FIVE TIMES to get to one of the Boyz. Each tab hit will cycle through the unit cards in the control group ONE BY ONE. Why is it like this? Why did you think this was a good idea? I've heard the argument that it's better for individual unit control, but people who want to select an individual unit in a RTS will do so as they always have: by clicking on the unit or clicking it's command card, so such reasoning makes no sense at all.
Take a look at these Warcraft III screenshots to see how unit type tab cycling functions:
I only have to press tab 3 times IN TOTAL to cycle through that control group fully, because the tab cycling of Warcraft III and StarCraft II DO NOT inefficiently cycle through individual units one at a time. In both of these games, all units in the control group are selected when you press your assigned hotkey, but the first unit (usually the most complex unit or hero) will show their command card. Pressing tab one time will shift to select ALL of the next units that come up and show their command card (the 7 Footmen). Pressing tab a second time switches to the next group of unit types in the control group (the 2 Knights). Pressing tab a third time will go back to the first unit (the lone unit / Arthas Menethil).
Please, don't make the game difficult for us to play. I would NEVER play StarCraft II or Warcraft III if they had the individual unit tab cycling system and ability cast mechanics that you have in Dawn of War III because those games would then be hard to play for all of the wrong reasons.