-reads spoilers for chapter 1167-
Yeah, Shanks being an ex-God's Blade (rookie level holy knight/god's knight, depending on what fan translations you read) was an obvious and he purposefully got the weakest tattoo of traveling within the summoning circles.
Or, the traveling via summoning circle tattoo is simply a rookie perk of your "dedication" to Imu.
So, the theory of Shanks losing his dominant hand/arm on purpose was because of him wanting Imu's seal off his person.
At least keep that basic perk to your advantage.
