EP content (XML tuning) and compatibility with base game ?

I'm currently modding all kinds of workout equipment (XML tuning). I need to mod both gym stuff and basketball equipment, so my mod will include both base game and City Living content.

I'm totally aware that the basketball related files won't work for people who don't have City Living installed, but I'd like to know if such files' presence inside my mod could cause bugs to them because of an XML that belongs to an EP they don't have. Can I safely combine base game XMLs and City Living XMLs in one package for everybody, no matter if they have City Living installed or not, or is it much safer if I make two different packages ?
Thank you in advance for your help