These particular people were already there (NE Hungary) in the 1780s
when surnames were generally adopted by Jews in this area.
I think your idea about the daughters is a logical one, but I don't
think it was a case of adopting the wife's surname per se: my own
theory is that when it came time to adopt surnames, they were already
a "tribe" or extended family (with sons-in-law, etc, already blended
I think they probably came >from Poland together (already with the
three different male genetic signatures among them). In 1780s censuses
of the area, I have seen the name spelled Heimli, Hajmlich, Heinrich
and Hermli, as well as use of patronymics for the same people (Ábrahám
Lázár, Dániel Zsigmond, and so forth).
The short version is that three men genetically unrelated along the
male line (but whose famlies probably all living as an extended family
or "clan") took on the same surname when it became legally required in
the 1780s. And conversely, in the FTDNA database are many people with
different surnames matching them (some of whom apparantly stayed in
Poland), but took on different surnames).
Heimlich surname project administrator