Honestly, if you gave it the same turn rate as a Defiant or an Escort Retrofit (17) it would still arguably be the best escort.
1. It would still be in a three-way tie for having the best manueverability.
2. It would have the strongest hull (+400 vs the Patrol, +1400 vs the Tactical, and +4140 vs the Escort Retrofit).
3. It would have the strongest shields with a modifier of 1 (vs .99 for the Patrol, .9 for the Tactical, and .77 for the Escort Retrofit)
4. It would have the best BOff setup, though since it's most common setups would be the same as either the Patrol Escort or Escort Retrofit, it's only a slight edge in flexibility over those two. It's unquestionably better than the Tactical Escort though.
5. It would be tied with the Patrol and Escort Retrofit for 4 Engineering consoles, better than the 3 on the Tactical.
6. It would have the worst number of science consoles at one instead of 2 for the others one of two areas where it is not the best or tied for first place.
7. It would be tied with the Tactical Escort for having the best tactical consoles.
8. Since the Tactical Escort is the only one for which a unique universal console exists, that is an advantage for it, and the only other way in which the JHAS would not still be the best or tied for first place. The Escort Retrofit has it's own universal console, but it's usable on any escort, and none of the fleet versions come with the consoles -- in all cases a lower level ship needs to be purchased in addition to the fleet one.
The JHAS would still be the "best" escort in almost every respect.
I didn't include the MVAE in the comparison, because it's a fundamentally different ship than the others. The Fleet Tactical Escort, Patrol Escort, and Escort Retrofit are all comparable, but with it's emphasis on science the MVAE is really a different thing entirely.
In it's basic mode, the MVAE is still inferior to the JHAS in almost every respect, but it would have the potential to beat the JHAS in turning in it's other modes if the JHAS were dropped down to 17 turn rate. Then the question would be whether the penalties the MVAE pays in it's other modes are enough to offset it's turn rate.
It needs something to compensate for the lack of a special console or ability. Any further needs would be discussed and tested on tribble.
The Average PvP player
1) Teamwork and timing is #1
2) You cannot "Kirk It" in every ship
3) You are going to die, just get back up