Not sure, but I am sure some people do that too. The ones I have talked to have their first one, then started one just free or cheap to play, using the experience they have already, to see how it progresses.
My alt and main are in the same alliance…my main gets jealous of my alt because the alt gets much better boards but has worse heroes so can’t take advantage of them…lol
A little off topic, but still having to do with familiars. As raids are more of an individually triggered event (regardless of alliance status), has any one ever encountered a raiding opponent who belong to the same alliance?