The kiss of death

When a tree gets brittle, it has to be axed.

You don't put rotten people with the help of your soldiers into positions of power,
because you can control them better than your soldiers.

You do that, because they are rotten and you can't command your soldiers to be so.

And once they are firmly embedded in an institution,
you can then axe that institution at a time of your choosing.

Arguably that is even desirable for your own institutions,
although you risk that somebody else learns of the rot
and axes your institution at a time of his choosing,
but then again it's far easier to refill an institution with fresh people
than to purge an infestation by unfit people from one.