When I mentioned to someone that my grandmother was baptized at the age of five into a church that practice infant baptism, their immediate response was that “the family had to wait for a pastor to marry them.” There was no convincing this person that their assumption was incorrect.
The church where Grandma was baptized had a regular pastor from the 1880s through the present day. Grandma was born in 1910.
While the area where Grandma lived in the 1910-1915 time frame was rural, it was not isolated and was fairly well settled. In fact there were more people living there then that there are today.
Make certain your assumptions are time and context appropriate. Waiting for a preacher of the “right denomination” might have been necessary in 1865 Nebraska. It was not the case in 1910 Illinois.
It never hurts to educate yourself and learn about your ancestor’s context.
It might not hurt to make assumptions, but it can sometimes give you genealogical headaches when you do so.