I feel like Gargos seems super random here. If you're just including it to make
Apex Devastator more playable, I'm not sure that's worth it. Instead, try one of these spicy sushi dishes:
Tromokratis An OG sea monster and the scariest
Taunting Elf ever printed.
Tolarian Serpent An oft forgotten self-mill gem if you ever want to capitalize in that direction.
Sharktocrab Actually the coolest card ever printed.
Simic Sky Swallower 70% of the time, this dude is a nigh-unkillable nightmare for your opponents. Flample and shroud are a sick combination.
EDIT: You also might want to cut some fat in general though to up your land count to 39-40 or so. In my experience, it really helps with the extra land effects to go a little heavier on real estate.