Idk how to explain this, but if a Pokemons Base Defense Total (HP + Def + SpD) is higher than the Pokemons Base Offense Total (Atk + SpA + Spe), it's HP, Def, and SpD become 120 whereas its Atk, SpA, and Spe become 80, vice-versa

EX:

Scrafty has 295 BDT and its BOT is 193, therefore, its new stat spread becomes 120/80/120/80/120/80

Lopunny has 225 BDT and its BOT is 235, therefore, its new stat spread becomes 80/120/80/120/80/120, the same applying for its Mega.

EDIT: I changed 60 to 80 so that priority moves aren't too over powered from certain Pokemon/Pokemon with Certain Abilities

EDIT2: I talked with Mamp about this, he said that Pokemon like Glalie should get 100 all around, and then the mega evolution will just get the same base form stats.