There's lots of merit in keeping it simple and accessible and I agree that should factor in an auto top 3 format of which I think should be kept. However I think that this specific one was missed the mark for the expert's pick for AD carry and I suppose Support too.
Whilst Perkz is a well known player, putting him in the top 3 for a performance based poll for a role he's never played competitively in ahead of the voted best AD carry for Summer 2018 in Upset and an AD carry who showed up in group stages last year as well as being a really consistent player for both splits in Attila seems odd. On top of this it has affected the agency of some fan's ability to put across their opinions through the poll. Whilst some fans might think that Perkz can be a top 3 performer this split, there are some fans who think G2 might perform poorly this split because of the move. Whilst fans can also think likewise of say S04 for keeping Upset, I am certain you would have lots more Perkz exclusions from a top 5 than Upset exclusions without an auto-included Perkz to top 5.
Similar points with Ignar, who some people feel won't be able to come back to form after what some people say was a poor showing in LCK and who has been known to have champion pool issues regardless in his disparity between play on engage supports and shield/healing supports which are likely to be a big factor this split with AD carry changes on the way.