No it wouldn't. The issue was primarily that passive spells like MS didn't have accurate effects because the db updated when provinces got interacted with or accessed their throne page or made operations. An attack sends out all horses, the prov would be updated as such, and again by the OP itself.
Ms is the most consistent example Zauper & hawk bring up when discussing the flaws of mehuls code... And it seems painfully minor compared to what we suffer through now.