without being big headed, imagine how many more playoffs CKC might have won if po's were only 1 rope, bng and 1 default (this was elite, pro or t17) back in the day.
I think that playoff format might prove to be really motivational to the majority of players, i know for example coming up against good ropers that would own me in ttrr or roper, i'd still stand a chance in elite and bng. I might stand a chance in beating Random00 or Mablak in a playoff if i pulled off the elite and bng victory which i have done vs both in the past. If it was vs komodo, again i might fancy my chances of beating him in bng (he is better in bng than me usually but we've had amazingly close games) but the rope scheme if he went with rope i might stand a chance as i learnt league style with middle hides, being consistent and thinking of cr8 placements, i beat dibz in some tus ropers a few time :p Same with anubis, diana, darkz, almog any top allrounders that this game has seen.. infact my only league singles victory was on wwp against almog in final because i won the bng and elite. I can still remember some of the clanner 1 rope, bng and 1 default loses... the worst was to EiF and finding out years later that they cheated because MrRaja was using silkworm.

So yes in a league situation i would totally favour the 3 playoff scheme options.
However that doesn't solve our current situation... which is activity of leagues and i think as i've said already this is down to either the oldschoolers coming back and playing again, or finding a way to motivate the new players of todays era into rank play.
Why don't we remove ratings? And add DONs and game limits? This would remove all the issues that Komodo pointed out, no avoiding would ever happen because;
a) you don't have a rating to risk if you lose (some good player avoid to keep their ratings if they were scared of losing to a better player)
b) you don't have to avoid if you don't like a scheme someone picks and you might lose because you can pick your prefer scheme and if you 1-1, both players either get 2 points, or you decide to make it 0-0.
I think this would let new players want to play because they could pick arial and mole shopper and still be rewarded for it, they might pick mole shop for all their picks in the league but at least they would be exposed to other more classic schemes, or different schemes that are not classic.
I admit it would need some thought to think it through, for example a ttrr is over in a few minutes and worth the same amount of points as a inter which could take hours if 3 rounds are used. But atleast it could bring everyone together and then we could pick a playoff system that follows the suggest model some people have mentioned of picking a rope based scheme, a default based scheme (elite, inter, t17), and an artillery based scheme, (bng, hysteria). Highest seed players pick first.
Suggested schemes accepted league schemes;
big rr
ttrr
(classic 30sec rr)
shopper
wxw
mole shopper
bng
super sheep racer (is this popular and would make new players want to take part?)
inter
elite
t17
hysteria
arial