I'm looking at the Serpent Gear, and I'm wondering if

The Drachen Mail,
165
strength +7 piety +7
Attack Power +7
increases tp during invigorate

The Serpent Sergeant's Tabard
defense 158
hp +60 strength +10 accuracy +5 enmity -20
3 serpent pieces add attack power +10

Or the Gridanian Officer's Overcoat
defense 150
strength +10 Dexterity +10 Intelligence +10 Piety +10
with a Sanction bonus of Critical Attack Power +120

I know the order is STR/ATK/PIE and to me it looks like the Serpent Sergeant's Tabard would be better than the Drachen Mail, especially because we don't worry about defense. But that increased tp is pretty wonderful. Then that Sanction bonus of critical attack power +120 looks pretty great as well.

I'm just not sure! I'm sort of new when it comes to stat crunching. Any help I would appreciate! And one more thing if I got aquired the Darklight Mail would that be better than these?

Thank you for any help!