1 strength = 1 armor
1 dex = 1 armor
1 vit = 35 life (before life% gear is calculated)
10 int = 1 all resis
This is why you will see a difference in toughness. The difference between #1 and #2 in terms of toughness is only 73 strength (73 armor). If you look at your overall armor, then you'll realize how little of an impact 73 armor is. For example, your barb might have 15,000-20,000+ armor. Also, a high end barb will eventually have 10,000-11,000+ strength, so 73 strength is pretty much nothing in terms of damage boosting as well. The raw damage provided by the weapon is the main thing you want to consider. Only consider the strength if you're comparing 2 weapons will similar damage ranges.
When it comes to worrying about toughness in general, you'll ideally never worry about getting it from your weapon. You'll end up getting your armor, resis, life%, and vit from other sources. Your weapons play the biggest role in determining how much damage you do, so it's best to always try to get the most damage possible, even if it means sacrificing some toughness.
None of the 3 weapons are ancient (potential 35% damage increase, plus higher stat ranges), and none of the weapons have been socketed by a ramalandi's gift. You'll eventually want to have ancient weapons with 4 main attributes+socket. Your ideal attributes will be damage range, 10% damage, strength, cooldown reduction, and socket. The second alternatives would be damage range, 10% damage, strength, vitality, and socket or damage range, 10% damage, strength, attack speed, and socket.
The next time you find a seemingly good weapon, screenshot and post here before you decide to reroll any attributes to make sure you don't ruin it.
Use #1.