Saag is the generic term for a curry of leafy vegetables (https://en.wikipedia.org/wiki/Saag), and Palak means spinach. Saag Paneer and Palak Paneer are often used interchangeably in the US.
The quality of these dishes does vary widely from establishment to establishment, despite sharing the same basic construction.
If you want a more oil-based Saag, take a look at our Saag tofu, which is dairy-free.