I don’t know, I’m not really a fan of IGOUGO and I kinda liked the card draw mechanic.
For solo/co-op it has the benefit of uncertainty plus it gives you the card with the information of who/what ever is up next.
For the Usurp mechanic you would then decide before shuffling the cards if you wanted to usurp and simply not put the character’s card in the shuffle.
Alternatively you could shuffle and flip all the cards simultanously building a kind of initiative track.
Then if you wish to Usurp roll 1d6( up to Vitality) and move your card that many spaces up the track.
Just my case for cards over die rolls for initiative, feel free to ignore it if you want
If you like small scale skirmish, check out http://planetares6.blogspot.be/?m=0