Yes, Marrow is completely sufficient for your preparations. The results of NEET PG & AIIMS in 2018, 2019, 2020, 2021 and 2022 have proven that you can secure a good rank by using Marrow alone, even if your rank in the previous year was low.

Marrow achieved a strike of 191/200 in NEET PG 2022. Out of 200 questions in NEET PG 2022, 191 were from QBank and Tests and190 were from the Videos. You can check out the screenshots of the Strik
here.

You can see the stories of average students who got a good rank by using only Marrow 
here.