From my experience with the Demo it seems that assigned groups in both Space and Ground battles do not match speed with each other.  This makes for some pretty disorganized attacks on my part when using the grouping feature.  Am I missing something or do units lack the ability to match speed when traveling in groups?  I notice that "guarding" units seem to match speed so I'm hoping I am just missing a click some where.

your right they don't match speed with the other units and there is no way to Affect a Battle Groups formation either which makes no sense because even if you put them where you want them they move out of formation. Delphi please say there are formation choices?

I dont know about ground, but in space grouped units match speed.

Take a formation of Impstars with tartans and order them to move. The tartans could easily outpace the Impstars, but they match speed.

i have noticed that everything always matches speed