I think you're looking at STR and END the wrong way. STR doesnt directly equate to the weapon rating nor does END relate to armor rating. You can see how each stat affects your character by opening the character window and looking at the lower section. Hover over each item there and it gives a break down of all the things that affect those areas.
I know that. Endurance = more Health. Armour = Damage reduction = less health loss = more Health. They equate to the same thing indirectly. Same with Strength. Strength indirectly equates to the damage potential. The weapon may not hit as hard like for like but your additional strength makes up for that. But without knowing what each equates to I'm unable to make a decision on whether one piece of equipment is better than the other.