Please walk dog!
Please walk, dog!
Two very different phrases. A small break in the phrase can change everything. And thats what I presume is happening with your progression. Some progressions are about where you're going; not where you came from. The progression isnt a I-ii. Its probably a ii-V-I, preceded by a I. For sake of consistency maybe its I, ii-V-I.
Aside from that, it is permissible for chords to go up or down, especially by steps
of course Im not TBlock or Gtrdave though.