Sub Weapon is confusing

Quote from Haikuno

So I recently used a +12 Upgrade (popo gift) on a lvl 38 Wand which has 140 + 238 energy and physical attack and in stats has + 17 energy attack. I was happy because it was so much better than the lvl 30 +6 wand I had before which only gave 111+71 energy and physical attack and + 23 energy attack in stats (which was pretty good imo). But when I tested my damage i noticed it didn't change at all. In fact, the lvl 30 wand would constantly deal the same damage or even more. So what's the point on uprading a wand to lvl 12 if a lvl 6 one that's lvl 30 instead of 38 will do even better just because it gives +5 stats difference? Is this a bug or am I doing something wrong?

same with my swordsman, cant see the difference

sub weapon only affects the sub weapon skills it doesn't affect glove based skills like spirit ball it will stay the same even if you have a wand + 15

Quote from XeoLee

sub weapon only affects the sub weapon skills it doesn't affect glove based skills like spirit ball it will stay the same even if you have a wand + 15

yea ik that but even when i upgraded my sword once to +11 it did same dmg with sword attacks on mobs and on other ppls