I think if you accept e.g. the Polish word (surname) "Rogacz" is equal the Croatian word (surname) Rogač in this article, you need to accept also Czech/Slovak surnames "Roháč".
And so way you has to consider other Slavic words/surnames e.g. (Russian, Ukrainian, Belorussian, Bulgarian,...) Рогач, Рохач.
In Hungary, when alphabetized "Rogač" surname (some hundred years ago, e.g. at the baptism, or at the first registration of the state) , a lot of times writes it in different ways, e.g: Rogáts, Ragács, Ragáts, Ragats, Rahács, Rohács, Roháts. (Changed [~missed] 1 or rarely 2 letters in the "Rogács" word, that word phonetically is the most accurate Hungarian version of the original Croatian word "Rogač".)
These ~Hungarian-written versions of original surname "Rogač" appeared without accent mark in USA (at the begin of the 20th Century, after the great emigration of Hungary): Rogacs, Rogats, Ragacs, Ragats, Rahacs, Rohacs, Rohats.
(I'm sorry, I cannot form above text...)
Greetings from Hungary :-)