See if you have solved the level-2 problems of DC PANDEY, then I think you have enough skill to solve the NCERT exemplar and it won't be that hard. I would recommend you to practice problems in a 1:1 ratio i.e., if you practice 30 problems every day then do 15 from DC PANDEY & 15 from NCERT EXEMPLAR. So I would recommend you to give the books equal importance, if you want to. But I would say, if you solve the previous year question+DC Pandey+Mock test, then it would be enough for JEE MAINS physics.

For more information regarding the JEE MAINS preparation tips consider the link below:

https://engineering.careers360.com/articles/jee-main-preparation-tips

I hope this helps. Wish you a great day!