Even better idea:
1.
STOP GIVING OUT THE BEST REWARDS TO ONLY 3 FELLOWSHIPS!!
Putting those typically previous event building grand prizes/better buildings as the later stage rewards would readily encourage a lot more participation on the whole.
2. Put more rewards on the main stages.
(especially on those waypoint intersections... some instants, small event decos, etc... are perfect for those spots!)
3. Leave the 'league' prizes as the new FA-exclusive buildings (and perhaps add an additional boost to them) + add in large packages of KP's (ie: 250kp for 1st, 150 for 2nd, 80 for 3rd), larger lots of Time Instants, plus additional goodies like multiple copies of the (soon to be)
Royal Restoration spell, etc...
I guarantee that those 3 changes would mean many, many,
many more fellowships would actively play in the FA's and gun for a top finish!
Most fellowships don't give a rat's fart about even attempting (or worrying) about ranking, simply because the prizes along the way are in no way worth even a fraction of the effort required to get them. (let alone the inevitable animosity that FA's foster within so many groups)
Worse yet, those fellowships that try for a top ranking, and then lose out by a few minutes (or even a major systems issue as happen during a previous adventure!), then see themselves drop from a 14hr instant + a building to a 5hr instant just end up ******* to no end, and left with such a bitter taste that they just refuse to ever participate in the future.
At least if the league prizes are less of an 'all-or-nothing', (ie: if you can't top 3 there was little to no point in playing), then there'd be a much healthier competition for everyone to get involved!