If we want improvements, then I feel we should have something more solid to base things on. So I check again with Smotherman. Not the best way to check it but again useable enough.
Turns out the Endeavor should only be at 92 points, the Endurance at 110 points and the Defiant at 110 points. This does not include the +1 to Boarding Roll cost which I feel should be added only to the Endeavor and cancelled out by the limiting rule on the other 2 variants.
As it is the Endeavor and Defiant is overcosted and the Endurance slightly undercosted. If we factor in the 6+/5+ prow, Endeavor goes up to 124.5, Endurance and Defiant becomes 132.5. So I think we can all agree that the armor values be built in though Endeavor and Endurance might need a bump from 120.
Weapons wise, I don't think there's a problem with the loadout of the Endeavor and Endurance. So here's a couple of ideas:
1. We up the Defiant's prow lances to Str 3 with 6+/5+ armor, then cost goes up to 150.
2. We just make the Defiant take Str 6 torps as prow weapons and it becomes and all ordnance ship with 6+/5+ armor, then cost goes up to 145.
3. We let the Defiant take Str 2 torps in addition to the Str 2 lances as prow weapons with 6+/5+ armor, then cost goes up to 150 as well.
4. We let the Defiant have the same FP2 WBs and Str 2 torps as the other 2 variants and with 6+/5+ armor, then cost goes up to 134.5.
If we use RCGothic's suggestion and we let the Defiant the same FP2 WBs and Str 2 torps as the other 2 variants and add FP2 dorsal WBs with 6+/5+ armor, then cost goes up to 137.5. Personally, I would prefer IN regular cruisers not to have dorsal weaponry and just up the prow FP to 4.
All 4 variants I propose as well as RCGothic's proposal still wouldn't result in a ship which can be comparable to the cost and effectiveness of the Dauntless, however. Again there might be stuff the Smotherman formula is missing but it's spot on with the cost of the Dauntless. The Dauntless just hits that sweet spot.