I completely agree with your opening line. The OP came asking for advice, and they are much more likely to take on board advice if it is given politely. I disagree completely with your second line. Any manager who is doing their job properly will take time to consider and ask why they have been asked to do something, what impact it is likely to have on those who are affected by it and if as may be the case in asking to see teacher's planning (depends on the exact circumstances) it is likely to create extra work and upset among staff. Having thought about these they should then raise any likely issues before they arise with their boss.