is Secondary chord (triad, seventh) can overlapping Fifth when is not substitute chord?

Question

i giving the situation. image is a resolution of V34

left case of the image is

'D-F' in V going to 'E-E' in I as contrary motion. and from that position, a 'harmonic connection' (any notes shared between two chords should remain in the same voice, and the rest of the voices move the shortest distance possible while avoiding breaking any other rules.) with the ii6's F-D is possible.

but right case of the image is

can't harmonic connection if 'D-F' in V going to 'E-E' in I as contrary motion. so F is going to up.

However, my curiosity here is that if V's 'D-F' goes to the I's 'E-E as contrary motion , can the following progress be made.

E-G-E-C -> D-A-F-A

I think that progression is can be harmonic connection. but as far as I know Secondary chord is can't overlapping Fifth. because 5 in the secondary chord is 3 in the primary chord.

but if is not substitute chord? can overlapping Fifth and Is it possible to proceed as above?

Answer 1

The chord progression described, V7-I-ii, contains two problematic aspects:

• It is the exception to double the third of a major chord — the I chord in this case. Since the third is not functioning as a leading tone, no rules are broken. However, the doubling is avoided, because it gives a hollow sound to the chord, as it does in this instance.
• There is a hidden fifth moving from I to ii between the soprano and bass parts. This is more problematic that the doubled third, especially since it occurs between outer voices.