Thought rerolling skin shards gave you skin for champ you owned

So i re-rolled some skin shards for champs i don't own, thinking i would get a "guaranteed" permanent skin for a champ i own.

Well, i did get a permanent skin.

Constable Trundle.

I neither own Trundle, nor wish to get trundle any time soon.

"FAQ: What happens if i get a skin for a champion that i don't own?" "If you’re not interested in unlocking that champ, you can re-roll a skin shard with three others for a guaranteed permanent skin or you can disenchant the skin shard and use the new essence to craft something that better fits your playstyle (permanent loot disenchants into more essence than shards)."

The issue with this is that, now i have a skin permanent i dont want. and grinding it into essence is kinda pointless considering i could have gotten 1125 Orange essence from the 3 shards, but only 375 from the Constable Trundle.

Basically, the answer from the FAQ in my opinion is partially misleading. It mentions not unlocking the champ and re-rolling for a guaranteed permanent skin shard. but it neither mentions random or a champ you own but the word "guaranteed" throws me off now. And it mentions that permanent loot disenchants for more essence than shards. albiet true, its also hindsight considering that you LOSE essence if you get a skin for a champ you DONT own nor want to unlock.

Any one else have opinions on this?