I'm visiting around 7-8 wrc events every year, so in my opinion from watching real: yes, not enough WRC1 cars, but please dont cancel wrc1...

when action starts, WRC1 cars makes so huge magic impression that leaves your breathless ... 6-7-8-9-10 whatever...
then WRC2 cars - top 4-10 drivers drives very nice, different cars, different effect, still nice to watch ...
and the rest - after top wrc and wrc2 - no bother...

so now proposal is to watch same top drivers driving wrc2+.... OK.. and after wrc2+ all other wrc2 will look booooooring.... as cars will look the same... but effect will be so bad... and we wont have 'magic' what nowdays WRC cars makes? no thank you, sorry...