Perfect, agreed. Just for your interest, I would have accepted also one different solution of the riddle, which would be Argeleb II. (if we took Lotho's rulership as over the whole Shire, and here the unlawful ownership would be even more strongly underlined). But well done!
I should also say, funnily enough, when I was making this question, I was considering at one point to write an untraditional riddle with several blank gaps to fill (like: Beren - X - X / X - Lobelia - Lotho), and your links are basically the copy of that