Time,
1.Rav Shlomo Aviner disagrees strongly with rav Melamed on this. With all due respect to REM (and he deserves a great deal), it is impossible for every soldier to have a personal rav who decides whether or not he should obey an order.
2. Since that article was written rabbis did indeed “rise up” and the order was changed to exempt any soldier who does not want to serve in a mixed unit.
Mdd, please cite your source and define what you mean by a “private army”. A kingship is by definition the rule of an individual. Thus, his army is the people’s army (Rav Kook, in fact, says that a king is, or at least should be, the embodiment of Am yisrael in an individual)