None of this makes any sense at all.
For creating a group designed for raiding, it makes zero difference if you have a linkshell or an FC to house those members in. The only important factor for gathering people for a raid is that you have them in the same place (in this case, a channel) where you announce and discuss the content you are doing so you can form said groups to do the content. A player can be FCless but still in a serious progression linkshell and completing the cutting edge content from day one.
The only advantage you have by being an in raid focused FC are the buffs and those are limited in what is useful. Even food duration isn't necessary, because any serious raider would have a means of providing that food so an extra 10-15 minutes duration isn't really an issue.