I’m not very good at this game but it seems as if you have decent leaders just not many units to back them up. It takes a while to get the units to surround your good leaders it took me like a year but that’s just because I was so on and off the game. Now I’m running a decent shadow dragon team because I got lucky. Just focus on the story and get your stones and just wait for the 3 year anniversary or an event that is coming to drop the stones. Don’t just drop stones are summons which you have no need for. I don’t think you should go for the UI goku and just move on the banner that comes after that. Just save up imo and wait for a good banner that has a wide range or units. Also start going to the story events, the universe survival saga has a really good Frieza who you can farm and would actually be a good addition and also the UI goku that you get from that story event. Go through the story events some of those units on there are great after farming them. Other than that save up for one of the following banners it is a slow process but eventually you will be able to beat most events. Just a few months ago I couldn’t beat anything now I can beat most events pretty easily.