Got an (disappointing) answer after some research..
Treaty visas are authorized on the basis of treaties of commerce and navigation between the United States and certain countries [..]. Please note that the Enterprise must be majority-owned, as well as developed and directed by nationals of the Treaty Country (“Treaty Country Nationals”), and individual employees must have the same nationality as the Enterprise to qualify.
Source
UPDATE:
~This now confuses me:~
Nationality: The investor (either a real or corporate person) must be a national of a treaty country and the entity must hold that same nationality. Under the law, a U.S. entity may qualify as an E-2 enterprise if it is owned by 50% or more by treaty nationals.
Source
~So since most of the other employees are British I may qualify?~ (~ = striketrhough)