Ok this is how I see it...
Doc Ock is useless. He has no range, and isn't very quick.
Grievous owns him just because he does. But I might add here that if Doc Ock was given four lightsabers, I believe the tables would definitely be turned.
Jango Fett is no doubt badass. I believe one blast from his gun would down either Ock or Goblin.
Goblin, I believe is being underestimated in this fight. As someone mentioned before, I believe he has the best maneuverability out of everyone mentioned. He also has near-Spiderman physical stats. Much like Jango, he also has some one-hit KO weapons. If he has the disintegration pumpkin bomb that his father had, one bomb would take out either Jango or Grievous. Since Grievous is limited to the ground, the battle is really between Jango and Harry. Like I said, if Harry hits him with a pumpkin bomb, then Jango is gone. But if Harry gets shot first then he is a goner. It all depends if his enhanced reflexes are enough. Overall, I would be more confident in Jango's accuracy.
But if Harry does somehow evade the first few shots by zipping around on his glider, and he gets up close to Jango, he will nail him much the same way he messed up Peter like a rag doll in SM3.
So in summary:
Grievous > Ock, but that doesn't mean crap since Harry is in the air, so its really Jango vs Harry, plus he'll probably in turn get his ass bombed.
Jango vs Harry - I'd give Jango the slight majority.