The problem is that there isn't anything for DT members to do unless there's solid proof that those four accounts have broken a forum or bounty rule or committed some kind of tag-worthy infraction. The evidence has to be solid enough to withstand scrutiny by the community for having been given by a DT member, because any DT member who hands out too many wrong feedbacks is going to get booted off the DT list eventually.
Thanks for your efforts to detect alt accounts. As a general forum member, I am pretty sure they are an alt account. But as a DT member, I won't tag based on the evidence that you presented here. Having alt accounts isn't a crime, but abuse & cheat with an alt account is a crime. So you may keep them on the eye to find more solid evidence that would help tag them. But I think they will be aware from now since accounts are already in question.
I don't expect anyone of you at DT to tag these 4 accounts based on the evidence I got, but you will have to research further to make a decision.
I'm just presenting some evidence that I think leads to something that can be considered strong especially regarding screenshot numbers, posting patterns and abuse of merit.
One of the strongest evidence at this time is Lantind is the alt of the other 5 accounts and he has been doing ban evasion. Then Davian144 and Bestcoins1 tried to apply for the same campaign but only Davian144 was accepted.