ΔE 21.8, loose: different enough that you should pick on purpose. Striking Scorpion Green is much more muted than Shamrock Green.
Can I use Striking Scorpion Green instead of Shamrock Green?
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 22). Striking Scorpion Green is much more muted than Shamrock Green.
Can I use Shamrock Green instead of Striking Scorpion Green?
The same difference applies the other way round: Shamrock Green is much more saturated.
ΔE is the colour difference between our two swatch estimates: under about 6 is close, over about 15 is loose. Real paints also differ in finish, coverage and how they thin, so test before you commit.