In halo wars where do you find super units? / xbox360?

[Stevo]

whenever i play halo wars skirmish or online and i pick captain cutter, sergeant forge , or professor anders i cannot find their super unit. i build every building i have and look through all of them but i cannot find their super unit. i can find the unique unit and leader powers but not the super unit. (...is there something wrong with my game?... do i have to finish the campaign to get them?... do i have to do more researches?...) please tell me and answer all my questions

 

[I am grunty]

For Captain Cutter, build a barracks, and upgrade marines as high as you can, they will become ODSTs. For Anders, build an air pad and upgrade Hornets as high as possible, and they will be Hawks. If you are Forge, build a Vehicle Depot and upgrade Scorpions as high as possible, and they will be Grizzlies.

 

[bobby]

For cutter you have to upgrade your infantry all the way for the ODST, for forge you have to upgrade the tanks all the way to get the grizzly tank and for anders you have to upgrade the hornets all the way for her hawks.