2/3s of the 3/4s of the remaining overs are usually bowled by other quicks though.
@kyear2 is correct. All the best sides since basically WW2 who have dominated test cricket have had
at least very good pace attacks. An attack like that gives you stability across different conditions because it's less conditions-reliant. If you have to rank these skills in importance, as the OP asked, how can it not be the skill set which is generally the most adaptable across all conditions which is the most important?
A great pacer will do a job on any type of surface. You only have to look at the records of guys like Marshall, McGrath, Hadlee etc to see that's the case. The same can't be said for even the greatest post-war spinners. Murali and Warne each have pretty big flaws in their records compared with the top pace bowlers.
As for top batsmen, obviously they're really important too, but at best in this sort of contest I'd have them on par with a spinner, or even a bit behind.
Welcome to the forum btw. Hope you enjoy it here