On my eye both versions fit. Your version fit more for more experienced players which played "Custom Game" at least few times and know that this is "one player" next to you, but for newbies better is current version as they see "multiple friends/people" around you : ).
Why this PR is not together with #14 as it is "one job"? There is possible to put single commit as PR or multiple commits... and ofc in single commit you can change multiple files too : D
allies is plural, and allies' is plural possessive. Change to singular possessive.