Well I actually collected all 4 sets and try all on, but from what I notice, archamge and ranger set is kinda poor even having full set on. The resistance they provide are extremely weak compare to the elite champion armor i using that time, which provide me 50%+ melee resistance, 46%+ range resitance and 50%+ magic resistance.
Itmes in D2 has random stats, generated like in DD1. So, you always can back @ the end of the game and collect all sets with twe stats you like.
Do not want a sword with poor magical dmg? Reload and reopen a chest again.
That's is.
Well as Xardas pointed out, all set armor stats are fixed. Beside that those specified drop by mind reading, example laiken sword also had fix stats, no matter how you reload, it will still be the same. Random item only happen on locked chest. From my experience, non locked chest items is all the time same.
That why I said that the set armors are kinda poor, beside the ulthring set, which has more balance bonus, enchantment slots and wont interrupt my accessories choice. Beside I find weapon drop by Baal is far more superior compare to those in the set item, at least all come with 3 enchantment slots. I got total of 6 enchantment slots through weapon by dual wielding.
I just tried the final battle in hard mode, still the divine being chop down in 1 to 2 thousand strike, where he still the 1st one laid dead compare to his minions, follow by Zandalor

. All is done solo without any creature or summon.