Most likely an issue of "how far people go with optimization". BTW, your Human Cleric in group is doing it wrong. Much "better" to kill something faster and heal only when needed (basically Spirit Guardians + Spiritual Weapons and then with the Standard action you either hit with a weapon or cast a spell, whatever appropriate).
About your fighter. Adding Dex modifier to Heavy Armor is just wrong. Even if others have higher AC (why do they????) This rule is there on purpose. With AC 25 you nearly get not hit EVER. This makes AC-Attacks sort of redundant... Also a shield with +5 AC magic bonus is too powerful for a L8 I would say, this would be a +3 shield (+2 basic defense bonus of shield and +3 more). Usually in our group at L5-8 we have +1 as highest magic bonus (so +3 AC instead of +5 AC). We even nerfed it that you only have either magic bonus from shield or from armor or ring of protection etc. -> only from one source. As a Houserule. So the stats don't go to the sky if someone gets a second magic item.
Your stats -> how did you get those? Waaaaaaays too high. A character without weakness is less interesting. If the other characters are also like that, they should check the point-buy-system which produces characters with strengths and weaknesses (you start with 8 on all values, and can spend 27 points, the cost are 9 for 1, 10 for 2, 11 for 3, 12 for 4, 13 for 5, 14 for 7, 15 for 9 - all before ability increase/racials kick in - so you usually have 1-2 16's at L1, possibly 18 if you play Variant Human and take Ability Increase, everything else usually lower and usually you have at least one 8-10 value, your weakness).
About the stats of the other players - is this really their average, how did you calculate this? So are you 100% sure that you are so much lower than them? I am especially pretty doubtful on the Ranged fighter's 110 damage per turn. Or did you count the Arcane Archer's special abilities here? He cannot do this all the time, remember!
I also wonder about the Rogue. Standard L8 rogue would be 4d6+1d8+4 which is 22.5 dmg (a bit more if fighting with two weapons, but usually he needs his minor action for other things than attacks). Only way to have a high dps rogue would be multiclass, for example the Booming Blade Rogue/Sorcerer which indeed can do pretty high damage.
Is it anyhow possible that you overrated the damage the others do based on "maximum damage in optimal situations" and then "buffed" your character (were these buffs like Dex-AC with Heavy Armor cleared up with the GM???) to counter this? Another possibility might be of course, that the other players do stuff like the -5/+10 feat which raises the damage a lot (in our group we actually nerfed it so you can only use it once per round - when I am GM actually it is even a "forbidden feat" - I hate it).
Asides from that, about Fighter optimization - despite ridiculous stats + magic items you did not look into some basic fighter optimization stuff:
- Go 2H, not Shield+1H. You seem to be a bit obsessed with AC, but you don't actually need it that high. And a bit higher AC is not as much worth as the capability to do more
damage. Standard for a Singleclass Fighter would be Great Sword and the "you can reroll 1 and 2" combat style (very nice with the 2d6 of the Greatsword ;-) ). Also you take
the feat where you can reduce your attack chance by 5, but adding 10 to the damage. This is basically must-have for a highly optimized fighter. If you have a magic weapon
you still should have enough hitchance and you hit then REALLY HARD. Taking +1 AC instead of being able to reroll 1s and 2s is really weak.
- Also remember the singleclass fighter is NOT the sustained dps king. He is an alphastriker. With Action Surge he can do a lot of damage first round and take one enemy "out"
first round possibly.
- Also if your friends play the "maximum optimization" game remember 2 levels Barbarian (multiclass) make the Fighter much more powerful.
- If you take the "reroll 1's+2's" actually it might make sense to go for the battlemaster instead of the crit-warrior. Personally, due to the special things he can do I always thought the battlemaster the stronger one.
- Normally, with Plate Armor AC 18 you should still have pretty strong AC compared to others (asides from some broken combinations like Heavy Armor Character + Shield spell).
Best regards,
Steffen
