I believe so, but I haven't tried this myself. Both apps need to support multiview, and I'm not sure if they do or not, as I don't use those apps.
I suppose it all depends on what kind of work you are doing and how you want to get it done. If it is an either/or question, the Macbook is hands down the winner, in my opinion, because it has a fully functioning operating system (OSX), a beautiful retina display, and a full range of powerful software (I have found DEVONthink, Scrivener, and Word 2016 to be pretty nice). Besides handwriting and reading PDFs, there aren't a whole lot of occasions when I feel like I'd be better off with the iPad.
If you are already using a Mac, iMac, MBA, or MBPr at home, and the iPad is an additional device, then I don't see any problem. I've particularly enjoyed using Scrivener (OSX) + notesy (iOS). Now that you have iOS with a split screen (finally), it is pretty easy to write with a PDF open on one side and your text on the other. I think you can open a non-mutli-screen app first and then open the one with support second if they both don't support the feature yet.
iOS is still terribly limited,though, so I don't think I would want to entirely give up OSX. Frankly, it is a pain to work with for any complicated task, and the better the Microsoft Surface Pro gets, the less convincing the whole low-power mobile argument is. But, technically speaking, it could be done, depending on how willing you are to discover and use workarounds for various activities. Perhaps undergraduates in the humanities would be able to get away with it, because there wouldn't be too much need for complicated formatting (at least, in my discipline), and they probably haven't amassed enough data yet to need search applications (I prefer HoudahSpot as a front-end for Spotlight) + external drives.
Personally, I tend to write a lot now on the Macbook with the iPad in portrait mode next to it (doing it right now, in fact). I considered (and still sometimes think about) getting a Surface Pro, but I do like to have my PDFs open on a large screen (the iPad), and I couldn't do that with the Surface. It's not a huge difference in weight to bring both devices around with me, and I'd sure miss OSX -- using the Surface Pro 3 for a while was not entirely satisfying. The only temptation for me with the iPad Pro isn't as a replacement for my Macbook, but as a way to view my PDFs at an even larger size.