I guess it's meant something like in C&C3, which can be seen in above cinematic trailer.
, starting at 1:19 (vid doesn't start where it should start).
Submarines emerging into the sky
(Sea-Wing/Sky-Wing), vessels going onshore and continue driving as tanks
(Tsunami Tanks)...
[Spoiler]I think 10 facs are more than enough. The possible unit combinations & exploits are great. Also the menu would be kinda broken, with new facs. 11 doesn't look nice, then we would need 12 - better not
Maybe enhance the planes fac by some special abilities like diving, as eg. the swift can be landed (which is a skill most users cannot handle properly). But honestly I wouldn't support this.
There are so many unit disucssions. And it always changes everything a lot ... big teams vs. small teams vs. 1v1. Total different games, total different unit behavier etc. - to solve something for team games can screw up 1v1 and vis a versa. While I get some intetions to change something, most of them I don't get at all.
[Spoiler]My loob brain got limited receptive skills
[Spoiler]