I agree with mmoncur in the basics. I don't think there are cubes too fast for anybody. Of course some will be more controllable for a beginner than others but this can also be modified with correct lubing, tensioning, etc.
Anyway regarding the conclusion that the best two cubes are Zhanchi and Weilong I disagree. Moyu cubes have become significantly better than Dayan and right now there are at least 4 o 5 Moyu / YJ cubes that I'd say are better than the Zhanchi.
If you really are thinking of buying two I would not get a Zhanchi and a Weilong because they are a bit similar in feeling (being the Weilong better IMHO), I would get a Weilong and another cube with different feeling to try and see what you like the most. For example, an Aolong (bubbly) or a Shengshou Aurora (buttery) or a Huanying / Liying (clacky) or a Sulong / Guanlong (don't know how to one-word define these, better approximation for Sulong would be elastic, but they are dirt-cheap both of them, so maybe you can throw in one of those as a 3rd cube for good measure, hehehe).
By the way, I didn't even recommend you my main, a YJ ChiLong because if feels also similar to the Weilong (not quite but somewhat similar) but you can try that one too if you want. Also I didn't recommend the Fhangshi shuanren even though it feels noticeably different to the others (sandy, scratchy and light) because I don't particularly like it and the colors of the stickers are terrible (orange is brown, yellow is mustard, blue and green are too dark and confusing under bad lighting..., I'm referring to the v2 57mm).