If that mod with 17 speed was a 5* mod, it would have 30 total speed. Only reason to use 3 or 4* mods would be if they have a good secondary speed. I have a few 4* mods with 10,9 or 8 speed
The arrow mod is the only mod that can have speed as a primary. They will finish with the same amount of speed depending on what * the mod is