The answer to this question, regardless what anyone says, is absolutely yes.

Multiboxing severely limits the need for other players, because lets be honest, (example)NO ONE is a better whm for me, than myself, and that's true for everyone. If it were "impossible" to multi box, there would be a MUCH larger outcry for merges.

But as it stands it's better to pay more money, to control more party members, than to rely on randoms. (plus it increases your income pretty dramatically, just sayin).