It’s definitely possible. I passed level 2 doing only schweser mainly because I had no choice. I just finished L1 in december and by the time I got my books had 3.5 months to study. I started reading the CFA text and quickly realized the only way was to grasp what was in Schweser. My gameplan consisted of reading and doing eoc schweser questions. After I got through all the material, I had a month to review. That’s when I switched to eoc CFA text questions and started figuring out my weaknesses.
I did pass L1 on the opposite method though. Read through all the CFA text and EOC questions and used Elan guides to review. It really depends on how early you get started. If you’re starting now, I’d use the CFA text. It’s way more interesting and not so diluted, but if you put it off, use Schweser.