But you wouldn't have to.
Even if you're from Bahamas, you can have 4 Lithuanians in your team, no?
but since you bring up the number four as advategeous again, i like to tell you an example of my home town team back the days since the german leagues was a pure legionärs league(rare cases where you had more then one german player in the rotation, not so rare case they had none).
We had a team with four/five player from the former yugoslawia and 5 americans. And the team got problems cause the players from yugoslawia isolate them in the team cause they prefered to talk their home language and so on, while the americans did the same in english(which is a bit better cause most people can talk english even the guys from yugoslawia). After that season, they looked to have a mostly american team cause it is possible to integrate to them.
Which i mean is following, one single person is easily to integrated in a team, 3-4 for a dangerous, around 8-9 you maybe have a core group but they should talk a common language or one that is desirable to learn by the team(which mostly is the native language)