DC needs to stop jerking itself off with its own history, constantly regurgitating old characters. One of the advantages of a reboot should be the chance to rid the company of the massive overproliferation of 'clone' characters, particularly as junior sidekicks. We don't need more heroes with the same or derived powersets.
ONE Flash. ONE Superman. ONE Wonder Woman. ONE Green Arrow. Etc. That should be the plan. Deviate only in exceptional circumstances. (I'll leave the Batfamily out of this, somewhat, as given that they have no powers, it only makes sense that proteges would have similar skill sets.)
But seriously, why can't heroes have proteges or sidekicks with different powers? I know that there are some beloved 'clone' characters, but that's mostly on account of a lot of time having been put into developing their personalities. If we just bite the bullet and kill them all off, writers can invest in new characters with unique powers who will also become beloved in time.
I would just kill off all the clones and/or change their powers to be unique.
Kon-El would go. Mon-El would go. There would be no Daxamites or other Kryptonians that show up in my universe ever. Supergirl would be re-written with some kind of watered-down Kryptonian powerset. (She could still be Kal's cousin--perhaps half-Kryptonian). Arsenal/Speedy would be gone. I might keep Black Adam, but there would never be a Mary Marvel or CM Jr. There would be a single Flash--Barry Allen. Wally and Bart would never exist. Not as guys with exactly the same powerset, at least. Donna Troy and the new Wondergirl would both never exist again. Green Lanterns are a Corps, so there would be more than one Lantern--BUT I'd make it so guys are good at doing different things with the ring, and most Lanterns would seem rather unique. Some make certain kinds of constructs, others are good at self-amping, others can generate TP or TK with the ring, others make basic shields and generate power blasts--really well, but they don't do constructs well. Etc. (And there would only be GREEN Lanterns. The entire emotional spectrum idea would be erased from continuity. Red, Blue, Yellow Lanterns--WTF?)
Fucking DC makes me crazy sometimes. Get some new ideas!