Hmmm, I think prot5 isn't necessary on the star armour...
Me and officepwnz123 Tested just prot4 armour and star armour with our swords at around 20-40. The result was:
~Prot4: we killed each other
~Star armour: We couldn't kill each other
We pvped for atleast 10 minutes with the star armour on and we both regenerated faster then we could kill each other.

In the test I did with MattBrpQc we saw that just prot4 we killed each other (key note: We both had 1000 swords)
in about 10 hits.
With the star armour we were still able to kill each other but it took 30 hits and 5 bow shots

Adding prot 5 to the star armour might be too op, I'm not saying it will be but the tests I did. It showed on an average scale a person with star armour in the arena will be almost unkillable to a player with lower swords.

For proof and evidence reply asking, I have no problem redoing the test and recording them for proof.

[All tests took place on my local server, and were all real pvp scenarios]

 

What enchants does star armor have right now?

 

Fire Res Pot.

 

Just get 1 or 2 swordsman and line up some people with 1k archery.