GT had no answer against the pace of Deepak Chahar, Mustafizur Rahman and Tushar Deshpande. These guys are not multi-million dollar buys like Starc or Cummins. But still they did their job today.
It was more of scoreboard pressure on GT that made those pacers look good.
Let's look at 15 Men's squad
1. Jaiswal
2. Rohit
3. SKY
4. Kohli
5. Wicketkeeper Batter (Jitesh, Jurel, Sanju (maybe) or ffs i hate it but possibly KL Rahul because of Dravid)
6. Seam All rounder Hardik
7. Spin All rounder Jadeja
8. Bowling Allrounder who can bat (otherwise tail would be too long)
9. Kuldeep
10. Bumrah
11. Siraj/Arshdeep
~~cut~~
The one with bold font will be a sure shot for every match, given they are fit unless there are some injuries or they are expecting any rest against any weak teams. Now tell me where will you fit the Rinku in this 15-men's squad?
That's good squad you have made, as long as Pandya and Jadeja are included that's enough for all rounder slots imo, so bowling all rounder's slot can be given to Rinku, of course in match he will come prior to Pandya and Jadeja.
Regarding wk slot, I also think it's KL who is going to get the wk slot, on alternative candidates you mentioned I personally think they have 0 chance.
Plus, What's difference between seam all rounder and bowling all rounder?