GMAT Strategy

Hopefully, I am posting this question in the right place. If not, I apologize.

I have started my Critical Reasoning portion of my study prep. I am working through the MGMAT study guide and the PowerScore CR Bible.

However, my biggest confusion here is the differentiation between approaches by the authors of these two texts. I am beginning to find it confusing.

So, here is my question:

Should I focus on truly one text...or should I use both and fill in the gaps in understanding where needed? This is an issue, since I am desperately trying to figure out the correct books. For now, I am using the MGMAT guides and flashcards found on here to study Quant...which is my absolute weakest point.

Thanks for any advice!