i know planet attack factors into invading, but does planet def factor in as well, also is that the attack o the planet before or after legion bonus.?

the formula
(played invasion attack/3)/(total planetary attack+defense+invasion defense)

don't forget to apply the legion bonus and any defensive %buffs or %debuffs to any invasion-only defensive buildings on the planet

and don't forget that some of your invasion attack modules are located outside of the weapons section of your ship
oh... and remember.... your regular attack buffs do NOT affect your invasion-only bonuses....