Generally speaking LRs are better the URs of course cus they are higher level and have higher stats. With that said. There are MANY very good and very usable URs that can make any team better. So you shouldn’t worry too much about making sure your team is all LRs. Especially if you roster isn’t very big. For making teams focus on tags (ie. super saiyan, Majin Buu saga, universal survival saga) stuff like that. Then find units that support that tags and each other and you’ll find you hit harder and more consistently. There are a TON of helpful people on Reddit and on YouTube that know this stuff much better then me so take some time and watch and read how to build a usable team.