To clarify: Which OS(es) do you need screenshots from?
“Factory install” makes it sound like you mean the stock OS from a phone vendor, in which case there are a lot of different looks on a lot of different phones.
But you want to compare so-called custom ROMs, so you mean screenshots from newly installed /e/OS, LineageOS, CalyxOS etc.?
Did you have a look whether such projects have the screenshots you want already online, something like Meet the Bliss Launcher -/e/OS’ default launcher perhaps?
Here’s a nice feature comparison table, by the way … https://eylenburg.github.io/android_comparison.htm