Honestly, I've found Ambuscade and Odyssey to be more fun when I'm not doing them, and I suspect Sortie bosses would be the same. Actually going in and doing the fight is just... do the thing, hope you pull it off. The fun part is between the fights, strategizing and trying to pick apart what worked, what didn't, and what needs to go into the next attempt. This in turn means... you probably aren't going to find any videos that really showcase the part of the content that's fun to do, it's just going to be "here's my group beating this boss."
That said, since I personally don't find FFXI as fun to watch as to play, I don't know of many channels that do group videos (I mostly see solo strategy videos tossed around), so all I can recommend is Velner, the guy on my server that I keep hearing does stuff on Youtube and on Twitch (and who shows up here occasionally too.) If anyone else can recommend any, please.
(I'm not sure why you'd want to avoid the wiki though. As a returning player you must know how utterly unplayable this game is without constant access to a wiki for reference.)