Martijn,
Take a look at this ticket
https://mantis.arcanoae.com/view.php?id=571.
I logged it some time ago (Oct-2016) when I was attempting to transition from ZIP based module installations to the RPM/YUM/ANPM ones.
Specifically, I attempted to get the RPM version of sdl/SDL installed, but ran into some problems. Eventually I lost interest as other priorities took over, but the content of that ticket will shed some light on the differences and specifically what is the correct one to install.
The last ticket update was done by Lewis, the key takeaways are:
"...
1. The SDL (and sdl) RPMs are not complete replacements for the zip-installed package you already have. In fact, SDLttf,dll is in a separate package entirely, now (SDL_ttf). I suspect that in time, the other SDL components will be packaged separately.
2. If you do have a need for the other SDL components, you might be better off sticking with the zip. I would put them in %UNIXROOT%\usr\local\dll, and just remove them manually when are able to get the rest of the set that you need via RPM.
..."
So in short, the RPM based SDL solution is not a complete replacement of the old ZIP based stuff. Until all the packages have been built you have the option to replace just what is available or simply keep the ZIP stuff running.