You couldn't be more wrong about this....both the RMT and ASLEF are democratic organisations their charter, policys and actions are all guided by members at branch level, resolution are proposed and discussed and voted on by branch members and these can ultimately become union policy as they are passed up the chain.
Usually , probably 1% of what they do is pay negotiations the other 99% of what the RMT and ASLEF reps do day to day is to cooperate and negotiate with management to come to agreements that suit both staff and company such as FDW agreements, Rosters, local agreements. They also hold management to account when they fail to honour agreements and also represent staff in disciplinary and competentcy hearings. You never hear about any of this in the daily mail, the sun or Mark Harper's press briefing or on Sky news.
Only when the negotiating machinery is exhausted is industrial action ever considered and then legally voted for by the required laws. There are no union barons calling the shots , just democratictaly elected local, regional and national union representatives doing what they have been elected by the members to do which is to represent those members wishes.
Never had theirs been more apparent with the continued solid turn out and votes for ASOAS and Strike manadates every 6 months in the ongoing dispute.