Just make sure your paintbrushes don't have spit ends like many do to hold paint...
I use FOUR Microfibbets, two on each side because they are easier to see when tying in and one can always break off one fiber off while fishing. With four I have a spare… ;-)
Unlike the tier in the video, I don't cut down the 'fibbets length until I am satisfied with the amount sticking out behind the hook and the complete tie in. It is a lot easier pulling them shorter when they are full length than cut close TO length.
Putting the 'fibbets off to the side of the hook shank so the thread torque pulls them on top is the way I go but I instead of using the cut-off tag to split them, when you initially tie in your thread, DON’T cut off the tag when you are done tying in your thread.
Instead, wrap your thread AND the tag back to the spot where you plan to tie in the 'fibbet, TRYING TO keep the tag on top of the hook shank while you wrap.
After you tie in the 'fibbets, use the single strand of tag hanging back there to split them. Because the tag is wrapped BACK to the hook bend, the harder you pull back on it, the wider the tail split will be no matter where they are tied in.
Wrapping back to the hook bend also gives you a less slippery spot to tie in the 'fibbets but when you pull back on the tag that was wrapped back with it, That will also pull back the securing wraps so you don’t see any extra warps beyond the tail tie in point.
Easy peasy and no glue required...
HTH