This mod allows you to create all barracks, stable, archery range, and castle unique units in groups of 4. This allows a much faster build-up time and larger, sooner battles. The group of four units costs the same as the original single unit and trains at the same speed.
This is currently a multi-player mod, as the AI cannot effectively play as the Vikings. If you wish to use it in single-player play, it works fine with all civs aside from the Vikings. The next update will address be fully single-player compatible. Please report any bugs so I can fix them for the update.