[tlhIngan Hol] they-them prefix with -moH -'egh with -moH and DoHmoH

[mayqel qunen'oS]

Suppose the klingons drive back the romulans from kronos:

tlhInganpu'vaD Qo'noS luDoHmoH romuluSnganpu'.

Now, lets forget this example, and consider the following one: There's
a starship closing in on another ship, and that second starship uses a
repellent beam to drive the first ship back. Now, the crew of the ship
which has been driven back wants to say "they drove us back from
them".

Suppose we write:

maHvaD DoHmoHta'. The problem here will be, that although there's the
null prefix for they-them, this prefix seemingly/apparently works only
when the two "they" and "them" are two different groups.

In the example above, since the subject and object of DoHmoH are the
same, we can't apply the null prefix in question.

Perhaps it would be tempting to write:

maHvaD DoH'eghmoHta'
they caused themselves to back away from us

Since with the {-'egh} the object acts on itself, thus overcoming the
they-them prefix restriction. But again, there's something seemingly
wrong with this sentence too, which I can't identify.

So, if I'm correct, the only way we can express the intended meaning
is by writing:

maHvaD Dujchaj luDoHmoHta'.

But am I right, or could the {maHvaD DoH'eghmoHta'} be correct too ?
Or could we use the they-them null prefix for cases where the two
"they" (subject and object) are in fact the same group ?

~ Qa'yIn