I don't have this thread notified or followed. Sorry for not being responsive.
From the beginning I intend to write a tonal progression, Wherever it starts it's always back to its tonic with a cadence. That's what tonal music is, Isn't it? After browsing and have some reading for awhile, now I recognize those two chromatic chords are secondary dominant with irregular resolution. If you familiar with "I got rhythm" - a tune written by Gershwin, that's the irregular resolution all about. Some say it's a dominant chain. Thus it would make the chords become non functional. Concluding this, we only have non-enclosed chords as the genuine one while the others as embellishment. Dm - G - (C7 - F7) - G - C.
I'm looking for more thought if you find this not justifiable. Thanks for replying.