Red Alert 3

Can´t believe theres no topic about it
I´m not a big RTS fan but have played Generalts a bit. As it was for only 5€ got it and having quite a bit of fun. Don´t know also about the RA:2 but I´ve read the storyline is a bit similar: Russians are time traveling and creating this parallel universe where you can plan your wars as Soviet, Allied, Imperial forces commander. The intermission clips have a funny note in it and some actors are quite good. Graphics are suprisingly good and demanding even for my HD6900 series CF. Gameplay is as I remembered from C&Q series.
Though what brought me to post this topic is some weapons I don´t get. Like mirage tanks, if you group them with other vehicles and order them to attack they just chill out and stay in one place. When you put other vehicles under their camouflage in base deffence they don´t react to anything. Don´t get it whats the point of them at all then? Using air forces anyways mainly as its been with Allies side.