Mechanized Ideal gets +X/+Y, where X is the highest base power among other creatures you control and Y is the highest base toughness among other creatures you control.
2018-09-03
If you control multiple Mechanized Ideals (or other creatures who's base power or toughness depends on other creatures), their base power and toughnesses will be applied in timestamp order after all others have been determined. If you have two Mechanized Ideals, the one that was played later will have 1 more power and toughness than the other.