Tl;dr summary: Rework “The Paratrooper” achievement or add paratroopers to tech tree to bring achievement in line with other class-related achievements, as current implementation is unbalanced.

For almost two years the paratrooper class has been locked behind a paywall on the Enlisted store, where you can purchase premium paratrooper squads for ~$40 USD, the only other way to acquire these squads is to have participated in one of a few events that all occurred pre-merge, or get incredibly lucky when opening a silver lootbox (though none are currently available).
As such, there is no way for a new or casual player who missed those old events to realistically complete this achievement, hence why at least on Steam platform, it is one of the rarest class-based achievements, at only 0.7% of the community earning the achievement:
while all other class-specific achievements have much higher completion rates:
Even the much more difficult to complete achievement “Specialist” that is locked to a single match, is at almost double the rate of the paratrooper achievement on Steam:
Therefore, it is my suggestion that the achievement should be removed entirely and replaced with a different class-specific task (guerillas maybe?) of similar difficulty
Add paratroopers to the tech tree with a slight nerf (similar to premium KV-2 getting mg, but tech tree does not) to keep the premium/tech tree squad balance intact so all players have an equal ability to complete all achievements, as many like to get 100% achievements in games.