Furthermore, there’s an unwritten rule the ultra-orthodox parties do not involve themselves or even voice an opinion on military matters
Only this isn't true Deri (of Shas and convicted felon) is in the war cabinet for crying out loud.
You are really naive if you think they don't get a say in everything that goes on, and deliberately ignoring reality if you can't admit that there diversion of funds for their own causes and communities has deprived the rest of the country not only of the security it needed on 7.10, but of health and social and community funding for everyone else, for decades.
The amount of power the ultra orthodox hold is obscene.
Mandatory service doesn't mean they don't get cushy jobs (if they want them) though.
Yair Netanyahu was never going anywhere near the front lines (he was in the Spokesperson's Unit), and nor do many other children-of (not only politicians of course, but they do have a lot of influence), they get jobs at headquarters or some other nice safe place, the military bands/entertainment units are notoriously where many a nepo-baby has got their start..