tldr.
Stop using 100% chance to hit. At least pick a target AC that will yield somewhere between 50% and 85% chance to hit or something like that. Do this anytime you look at sneak attack or sharpshooters -5/+10.
.64 is the chance a sneak attack lands when using 65% base chance to hit after -5/+10 sharpshooter and 2 attacks.
.4 is the chance to hit after the -5/+10 sharpshooter assuming 65% chance to hit.
As his analysis shows. Using 65% base chance to hit means the high sneak attack rogue version does more damage.
Against what AC? your doing what your accusing me of! lol. I don't need a base AC because I am giving Damage per hit and then stating that hits will be variable on AC (Which I was wrong for saying DPR because that is inaccurate). And Your saying:
Fighter 5 / rogue 15, fighter 11 / rogue 9 and fighter 20 do about the same DPR over progression. IOW, at level 15-19 the rogue MC will do more damage than the pure fighter, but at level 20 fighter does better.
Curving shot is the main reason stopping at fighter 5 is a bad idea. Beyond that, I don't expect balance to be different as your arcane shots are more limited than BM's SD.
If you have SS (which you should), you are removing some attacks at 1d8+15 for 5d6 to 8d6 SA damage. For instance at level 15, you are exchanging your 3rd attack (roughly 10 DPR ~ 1d8+15 * .5) for SA damage (13 DPR ~ 5d6 * .75). Overall not a big gain/loss in damage.
If you MC, I wouldn't do it before fighter 5. I would MC to rogue 3, then fighter 7, then rogue 9 to finish at fighter 11 / rogue 9.
It all comes down to which build matches your RP concept and has the best utilities.
My point is you can't have one DPR for not set AC and since you didn't list one your answer is incomplete where mine is not though less mathematically accurate it provides the means for some assessment using total DPH.
However ....
20 sided dice = 5% chance to roll any number
+ hit modifier (Dex 20 so 5 + proficiency levels 5 to 8 are +3 - 5 for Sharp shooter +1 Magic arrow, +2 Archery Fighting style) = So +6 for levels 5-8 or +7 for level 9-11
- (AC -1) to remove the missing roles, the -1 is because if you meet the AC it is a hit.
Then multiply that number by the 5% value of each number you can roll on a 20 sided dye to determine the chance to hit as decimal or multiply by 100 for the percent.
level 5-8 vs AC10 = .85 or 85%
level 5-8 vs AC15 = .6 or 60%
level 5-8 vs AC20 = .35 or 35%
level 9-11 vs AC10 = .9 or 90%
level 9-11 vs AC15 = .65 or 65%
level 9-11 vs AC20 = .4 or 40%
Now Sneak attack is different because you have to figure out the chance it happening if at least once with 2 attempts. My understanding it of that formula is:
1st attack = % Example: .85 or 85%
2nd attack = Inverse of 1st % X % + Last total % Example: (.25 X .85) + .85 = .9775 or 97%
3rd Attack = Inverse of 2st % X % + Last total % Example: (.0225 x .85) + .9775 = .996625 or 99%
Corrected for the revised arcane archer with percent to hit for proper DPR.
level 6: Possible Ability Score Improvement or Feat
VS AC10
Basic Attack (1d8+15) = 24 X .85 = 20.4 per basic attack
Sneak attack for 2 attacks 1d6 = 3.5 X .9775 = 3.42125
Rogue 1 / Arcane Archer 5: (20.4) + (20.4) + (~3 SA) = ~44 DPR
Arcane Archer 6: (20.4) + (20.4) = ~41 DPR + Crossbow expert?
VS AC15 <-- 14.25 is the average for all the monsters in the book, while that does not reflect what your DM will make you fight its not a bad place to start.
Basic Attack (1d8+15) = 24 X .6 = 14.4 per basic attack
Sneak attack for 2 attacks 1d6 = 3.5 X .84 = 2.94
Rogue 1 / Arcane Archer 5: (14.4) + (14.4) + (~3 SA) = ~32 DPR
Arcane Archer 6: (14.4) + (14.4) = ~29 DPR + Crossbow expert?
VS AC20
Basic Attack (1d8+15) = 24 X .35 = 8.4 per basic attack
Sneak attack for 2 attacks 1d6 = 3.5 X .4375 = 1.53125
Rogue 1 / Arcane Archer 5: (8.4) + (8.4) + (~2) = ~19 DPR
Arcane Archer 6: (8.4) + (8.4) = ~17 DPR + Crossbow expert?
--- This is were it got late, I got tired and went to bed, lol. If no one sees has a correction for me I will try to remember and finish tomarrow and add the Revised ranger since the OP added this:
A reminder to a few of you that I am playing the revised arcane archer. Also, I am now heavily considering taking a 2-3 dip into the revised ranger. So maybe go fighter 7, then go ranger 3 then back to fighter.
level 8: Possible Ability Score Improvement or Feat
Rogue 3 / Arcane Archer 5: (1d8+15) + (1d8+15) + (2d6 SA) = 48.5 DPR
Rogue 2 / Arcane Archer 6: (1d8+15) + (1d8+15) + (1d6 SA) = 45 DPR + Crossbow expert?
Arcane Archer 8: (1d8+15) + (1d8+15) + (2d6 hex) = 48.5 DPR + Crossbow expert? + Magic Initiate for Warlock Hex?
Level 11: Possible Extra Attack
Rogue 6 / Arcane Archer 5: (1d8+15) + (1d8+15) + (3d6 SA) = 52 DPR + Uncanny Dodge + Expertise
Rogue 5 / Arcane Archer 6: (1d8+15) + (1d8+15) + (3d6 SA) = 52 DPR + Crossbow expert? + Uncanny Dodge
Rogue 3 / Arcane Archer 8: (1d8+15) + (1d8+15) + (2d6 SA) = 48.5 DPR + Crossbow expert? + Magic Initiate?
Arcane Archer 11: (1d8+15) + (1d8+15) + (1d8+15) + (3d6 hex) = 71.5 DPR + Crossbow expert? + Magic Initiate? + Indomitable