STATS:
Shaymin (Land Forme)'s BST is 600 and its stats are 100 for all 6 stats. It's other form (Sky Forme) has the same BST as the other Forme, but it receives +03 in Attack, -25 in both Defense and Special Defense, +20 in Special Attack, and +27 in Speed.
Exeggutor (Kantonian)'s BST is 530 and its stats are 095 in both HP and Attack, 085 in Defense, 125 in Special Attack, 075 in Special Defense, and 055 in Speed. Its regional variant's BST is the same as its Kantonian form, but it receives +10 in Attack and -10 in Speed.
MOVES:
Shaymin (Land Forme) can learn Normal- and Grass-type moves through level-up. But, its other Forme can also learn Flying-type moves through level-up. Both Formes can learn Normal-, Grass-, Psychic-, and Fairy-type moves as TMs.
Exeggutor (Kantonian) can learn Normal-, Grass-, and Psychic-type moves through level-up. But, its regional variant can also learn Dragon-type moves through level-up. Kantonian Exeggutor can learn Normal-, Grass-, Poison-, Psychic-, Bug-, and Dark-type moves as TMs. but, its regional variant can also learn Fire-, Fighting-, Ground-, and Dragon-type moves as TMs. Both forms can learn Normal-, Grass-, and Rock-type moves as egg moves.
TYPING:
Shaymin (Land Forme) is a pure-Grass-type: making it resistant to Water, Electric, Grass, and Ground; and weak to Fire, Ice, Poison, Flying, and Bug.
Its other Sky Forme is a Grass/Flying-type: making it immune to Ground; resistant to Water(1/2), Grass(1/4), and Fighting(1/2); and weak to Fire(2x), Ice(4x), Poison(2x), Flying(2x), and Rock(2x).
Kantonian Exeggutor is a Grass/Psychic-type: making it resistant to Water, Electric, Grass, Fighting, Ground, and Psychic; and weak to Fire(2x), Ice(2x), Poison(2x), Flying(2x), Bug(4x), Ghost(2x), and Dark(2x).
Its regional variant is a Grass/Dragon-type: making it doubly resistant to Water, Electric, and Grass; and weak to Ice(4x), Poison(2x), Flying(2x), Bug(2x), Dragon(2x), and Fairy(2x).
By stats, Shaymin has a higher HP stat(100 for Land Forme), Defense stat(100 for Land Forme), Special Defense stat(100 for Land Forme), and Speed stat(100 for Sky Forme) compared to Exeggutor. Exeggutor has a higher Attack stat(105 for Alolan) and Special Attack stat(125 for both forms) compared to Shaymin.
By moves, Alolan Exeggutor can learn 4 different types of moves through level-up compared to its variant(3), Shaymin (Sky Forme)(3), and Shaymin (Land Forme)(2). Also, Alolan Exeggutor can learn 10 different types of moves as TMs compared to its variant(6) and Shaymin (both Formes)(4). Exeggutor (both forms) is the only one out of the two than can learn egg moves(3 different types of moves), since Shaymin (both Formes) is a Mythical (or...Legendary...I don't know).
By types, Shaymin (Sky Forme) has one more immunity than its other form and Exeggutor(both forms). Kantonian Exeggutor has 6 resistances compared to its variant(3), Shaymin (Sky Forme)(3), and Shaymin (Land Forme)(4). Shaymin (both Formes) have the fewest weaknesses (5) compared to Alolan(6) and Kantonian(7) Exeggutor.
