Yes, i mean Adventurer 5 gives 37.5% move speed and damage, so it definitly would give more move speed with only one affix. Now you use momentum + 1 move speed affix. I will look if i have any move speed items and see if momentum gives more dmg or not.
Edit: I'll get back here when i get legendary with momentum to test it
But fast work is:
10% ms from hero and 15% ms = 25%
25/2 = 12.5 % dmg increase
Adventurer gives 37.5% dmg increase so its 25% more and gives 37.5% move speed so it's 12.5% more. The only problem is you need to collect gold but i thinks it's not much of a problem.