Similars with different words - Acceptable?

[Nikovsk]

So I have a great idea for a series, it's a simple image yet with a strong concept.
It's applicable to several situations, so I would like to create about 10-15 images changing only the text - one word.

I have seen contributors with hundreds of similar images changing only the word, color or slight variations.
Agencies have software to detect similar images, so I would like to know your experience dealing with this situation.

Should I change the background always or it's acceptable to modify only the text?