original thinker,
Mosheh Rabbeinu and Dovid went to war based on a command from Hashem. When tzahal gets a navi or an urim vetumim then we can compare. Until then you’re comparing apples to oranges.
And even if they did somehow get themseves a navi…when Moshe Rabbeinu or Dovid Hamelech went to war, it was announced that anyone who had built a new house or got married etc should go home. They then announced that anyone who is afraid should go home. Chazal tell us that this refers to people who were afraid that they won’t have siyata dishmaya because they had done aveiros. In other words only tzadikim gemurim went to war.
When you find someone on that level then we can discuss your question. For the rest of us who aren’t there yet, they don’t belong on the battle field, even if tzahal had a navi directing them.