This is why I prefer to think less about roles or designations and more about resources. How much batting (from the best batters through to guys who can both score effectively or hold up an end) and how much bowling (how many overs are in the side).
For the latter, I've decided to call this the OTB Rating (Overs in The Bank) cause it sounds more complex than it is. It's not really scientific, is fairly subjective but it gives you a rough idea of the depth and options a team has. You've got frontline bowlers that I would consider 10 overs. Then it's kind of how many would you want from a player, doesn't have to be the maximum or minimum but more well that seems like a comfortable amount to have that player bowl. All rounders might be 6-8 overs, your part-timers that might 2-4 overs. Doesn't mean they can't bowl more or fewer overs... you get the idea, I'm sure.
Look at the teams yesterday:
Australia. The four front line bowlers makes 40, I'd put Maxwell and Marsh in the 6-8 (let's say 7) and Head at 3. So they've got plenty of overs in the bank, minimum 57-60. They've 37 overs off pace, 20 overs off spin. Some players could bowl more or less depending on the circumstances.
The India side yesterday had 50 OTB. Five bowlers who have to bowl 10 because I don't want anyone else in that side bowling at all. This isn't memeing around in a dead rubber, with 400 on the board, against an associate, it's the World Cup Final. If you're telling me Kohli is a sixth that's like saying David Warner or Dawid Malan are sixth bowlers (and Malan averages 32.36 in List A, not 148 like Kohli). You put Hardik in that team and the bowling attacks don't look much different.
I think in terms of Indian part timers, pretty sure Shastri talked about this recently on comms. When you get in the Indian side (or when you get in an IPL side), there's no need to bowl. They've get net bowlers, they've got bigger squads than they would have had 15 years ago, and they have coaches with slingers. So, guys just don't need to bowl unless they make that choice or are pushed to do so.
The fact that Indian players don't play overseas may also be a factor. Liam Livingstone makes himself a far more appealing signing to franchises around the world when he can bat, field and bowl 4 overs of two types of spin. That in turn makes him a valuable England player and probably was the reason he got called up to the test side despite having played a lot less first class cricket than when he was starting out. Glenn Phillips can bat, bowl, field and keep wicket.
That's why the impact player rule seems counterintuitive to what Team India needs. They need these triple threat players and back ups in case one gets injured but they aren't going to find them in the IPL or SMAT anymore whilst they can just bring in a specialist to fill the role of a part timer. Of course, I still think the BCCI could well force through the rule internationally because they would stand benefit the most. Say Jhah gonna Say Jhah.
Essay over.
The impact of having to develop a secondary skill to make yourself a better prospect for overseas leagues is something I overlooked.
Australia are a bit of a unique case at the moment due to some of their better batters being all-rounders by trade and getting into the side due to that rather than a strategy of packing the team with dual role players. It was held against them as a weakness of their side before the tournament. They made it work at important junctures due to some superb planning but I don’t think any other side in world cricket can pull it off and I doubt any side will look at this one as a model to replicate which wasn’t the case for England circa 2019. It’s not too dissimilar to England picking a bunch of bowling all-rounders or bowlers that can whack the ball not necessarily because they could do it but more so because they were their better bowling options at that moment.
The impact player rule will inevitably hamper some development but I think a cultural shift also needs to happen here. The Indian side and a lot of fans seem to want six blokes out there that can make the team just on batting (average 40+ basically) which hasn’t been the case with every other international side out there at the moment with the exception of South Africa. The latter were willing to develop Markram to plug in the gap so that it becomes possible. India have not one but two players capable of doing that in Tilak and Jaiswal. The question is if they’ll get them doing it across all levels of cricket?