No need for another player to test this offline! Jump into training mode and try it out. If that combo counter counts the whole thing together (example “2 hits” for just the overhead to cr.mp), then there was no chance for Guile to flip on you between them
Check out this thread.
All strengths of Dash Swing Blow on hit put you ten frames of freedom ahead of your opponent (your overhead attack recovers before their reeling “hitstun” animation ends so you can act again a whole sixth of a second before they can), which gives you all the sweet, sweet time in the world to pop in another normal. Rog’s crouching strong gets to the good part in only six frames so it is guaranteed after with nice, juicy four frame window for the input (one fifteenth of a second, which is actually lots of time). The frame data that allows us to see that this is possible can be found here.
If you got hit out of it, you were either in a really laggy game or you need some practice with the timing.
As far as the bigger picture goes, remember that if your opponent blocks your DSB you’ve handed him a guaranteed combo. (Your overhead attack recovers a few frames AFTER their “blockstun” animation, so he can start hitting you while you’re still pulling your arm back in).