Yeah you´re right, the Union needs some players. But I think they need new players, from mm russia or public players. If you have some people from mm russia regiments, they will bring more people to you (the 15th Alabama doesn´t really recruit anymore, because most of the new recruit come from mm russia by other players, who are in the regiment yet).
But the point is: The Union really needs more players, otherwise the confederacy can play with itself one time...