In a lot of ways it is probably fairer if both semis are on the same surface. It doesn't then give a shale/tarmac specialist a big advantage or perhaps a big disadvantage depending on which semi they are in.
I have often thought that perhaps we look at the World Championship all wrong these days. Back in the days of a single car for both surfaces the approach was fine, but now we almost have two disciplines within the same sport.....there are specialists on each surface, and indeed one surface only racers.
In a year when the final is on shale, we (should) have a tar and a shale semi.....a tar only racer might get lucky and get the tar semi, but then has the prospect of a shale WF.....great to be in the WF, but a largely pointless exercise for his chances of success? He might have got the shale semi, and his chances of getting to the WF are slim anyway, then he has another shale race in the WF if he is lucky enough to get through. A single surface racer has the odds stacked against them......the final has to be on "their" surface, and they need to be lucky in how they fall for the semi.
If we are not going to try to move back to one car for both surfaces with rule changes (as seems likely), is it perhaps time to look at alternating the whole championship between shale and tarmac, with both semis being on the same surface as the WF? It would either be a shale year or a tarmac year.
Obviously there is a school of thought that the World Champion, the highest accolade on offer, should be one of the best drivers out there, having succeeded on whatever surface is available, but things have changed rather dramatically over the years with regard to the specs of the two cars (shale and tarmac) and this puts the single surface racer at a disadvantage......however good he might be on his "chosen" surface.
Single surface racers exist for many reasons, perhaps budget or just personal choice.....but should they be discriminated against, put at a disadvantage because of this? For the sake of argument, let's take current Champion Nigel Green.....he was very, very good on tarmac last year......he was pretty good on shale too, but lets (for the sake of argument) assume he didn't race shale. If he got the rub of the green and got a tar semi, he was a big favourtite for the title in the tar final......however, a shale semi would have knocked the chances of (arguably) the best tar driver taking the gold.
This isn't about favouritism, it's about moving with the way the sport has been going for quite some time......the system was fine back in the 70's and 80's.......but is it fit for purpose these days?