
Creature — Human Knight
First strike
When this creature enters, if an opponent controls more lands than you, you may search your library for a Plains card, put it onto the battlefield, then shuffle.
2/2

White Knight that fetches lands from library, similar land-ramp role.

Catch-up ramp when opponents have more lands, classic white fixing.

Two-mana white creature that fetches a Plains when behind on lands.

Creature that ramps by putting a land onto the battlefield.

White creature offering land recursion and value, strong recur target.

Two-mana white tutor-on-ETB creature in the same aggressive role.

Colorless body that sacrifices to fetch basic lands for ramp.

White creature that tutors lands when opponents have more lands.
The Plains you search for doesn't have to be basic. For example, you could put a Sacred Foundry onto the battlefield.
Knight of the White Orchid's triggered ability has an “intervening ‘if' clause.” That means (1) the ability won't trigger at all unless any one of your opponents controls more lands than you, and (2) the ability will do nothing if you control at least as many lands as each of your opponents by the time it resolves.