The more general problem is conservative activists don’t try to get control of these groups, but leftists are always available to corrupt everything.
You completely and utterly misunderstand how Amnesty International is structured.
The only way to affect Amnesty International in any way, shape, or form would be to become a policy maker in Washington or Brussels in charge of one of the organizations that actually are Amnesty International.
Local chapters have no input of any sort, nor does the main organization send representatives down the ladder who interface with them at any time.