It depends on how you play music.
I'll talk about my experience: the Little Phatty goes very well with the Nord Lead series. I guess a Nord cannot be a bad partner for a Voyager then.
The Nord character is very complementary and will provide really good polyphonics -pads, strings- as well as cool leads, not in the Moog vein though. When it comes to bass, I usually think Phatty rather than Nord Lead, but why not: I'm doing this automatically as my fingers find their way on the knobs easier with the Phatty in that situation.
Last but not least: the Nord interface is really hands on, just as the Voyager's. If you're a keyboardist, you'd find yourself with a set-up allowing playing as well as live tweaking.
About the Evolver, I had one: it's quite a little beast, with uncommon possibilities. Pay attention to the encoders, they are lifetime-limited… If you're a keyboardist, you certainly prefer the 3 octave version, which is harder to find than the desktop one.
If you want polyphony, you have to know the PolyEvolver will sing of its 4 voices, which is sometimes limited. Actually, it comes to how you play music: live, studio only, with your fingers, with a sequencer…
For the story, I wanted the Evolver since it came out. I got the desktop one last year and sold it 6 months later. It definitely is a great synth, but I was fed up with programming patches rather than playing music. The Phatty entered just after…