Pace without skill and results is as useful as red lights in grand theft auto.
Thakur and Natrajan bowled a million times better than Naseem Shah and Musa (was it in 2019). India had a very similar attack in terms of experience going into the 3rd test in Aus in 2021 to Pakistan’s bowling in 2019.
We know who bowled better
An often overlooked aspect is FC experience when we talk about young Pakistani pacers debuting in Aus. Why selectors did that with selection is a different debate but, Naseem and Musa combined had around 10 FC matches between them while Shaheen had 4 test matches and around similar number of FC matches behind him.
While the bowling attack of India did not have much Test experience they had somewhere between 175-200 FC matches (Siraj, Saini, Thakur, Nataranjan) between them along with a good amount of A team experience. They were performed really well without a doubt.
3-4 youngsters debuting/new to test cricket with high potential but, with less than 15 FC matches combined will 9/10 or maybe 10/10 times be outperformed by 3-4 pacers with maybe a lesser overall long term potential (I think Siraj is pretty solid) but with over 170 odd FC matches with decent stats.
International sports are tough, you cant win or perform based upon potential alone. There is no way to prove so you can invalidate my this point but, quite a few number bowlers from within Pak domestic setup who would have had atleast 2-4 seasons of FC cricket behind them would have outperformed Shaheen, Naseem and Musa on the 2019 tour of Australia. Selections were heavily criticized even back then by quite a few. Imagine Umran Malick or any other young pacer from India debuting in Aus without even playing handful of FC matches, that wont happen as India has a settled bowling lineup so youngsters will get time to develop. Despite the fact that Amir, Wahab retired, Hassan got injured, selectors still could have done much better in selection rather than launching young ones with raw pace without anything behind them in Aus.
I agree with your statement that Pace without skills is useless and have mentioned it a few times myself. Thing is that pace in some bowlers can come naturally even when they are raw, skill development takes time and that can't happen without playing FC cricket. Judging Naseem the way he was judged just because he was playing international cricket was wrong in my opinion. He should have been judged in combination with fact that he was not supposed to play international cricket when he was selected. If he would still have been playing FC cricket and would have debuted just now or few months or year from the now than judgement would have been justifiable and most probably different as well because people often go by first impressions against top teams but, Naseem's impression was far from what he would have left with more FC numbers behind him.