I don't have a great knowledge about UK union finances, nor of USA rail unions, but did understand that one mainstream difference is that in the UK dues payable are a fixed fee per member, possibly in several bands by trade, whereas in the USA it is a percentage of pay (and notably much higher than the actual percentage in the UK). Thus the union's management financial desire (quite separate to that of any members) is in Britain to have as MANY members as possible, and to thus resist any efficiency scheme that reduces the future size of the workforce, whereas in the USA it is more about maintaining and increasing high incomes for the members.
I am guessing that a significant part of the issue with guards being portrayed as "redundant" instead of becoming higher-paid drivers (which to an outsider seems a perfectly reasonable career progression to offer, especially given the continuous shortage of drivers) is that historically they have been in separate unions.
I've been wondering about this. RMT would lose revenue if guards transitioned to driver roles and switched union.
RMT subscription income, across all its membership, was £18.4M in 2021 (Nov/Dec '22 edition of RMT News:
https://www.rmt.org.uk/news/rmt-news/)
Their fees are £300 a year for anyone on over £23k (
https://www.rmt.org.uk/about/join-rmt/) - and about half that for anyone on less. Membership is about 80,000 - the "R" in RMT is the most significant part of their membership.
10,000 guards (guessing, and happy to be corrected - TOC RMT members is a good bit over 20,000 in total but includes 10,000 cleaners probably largely on reduced rate subscription). £300 each a year per guard - that's £3M. A gradual decline in numbers would be a painful prospect for RMT.
18,000 balloted this month at Network Rail across signallers, maintenance and other roles - even the voluntary severance scheme (5% of NR employees) would've cost RMT £300k in lost fees - or 2% of its membership dues..
Also, if you can't get a pay rise for your members, you'll have trouble increasing the fee by any higher percentage to recoup that decline and inflation which are needed to pay RMT's own staff (who can themselves go on strike!)
On the other hand, for ASLEF - as a union that'd be great as their fees would increase, but for ASLEF members who may be earning a lot from overtime - the members would earn less of that if there were no driver shortage! The railways would benefit a lot from a passenger perspective if crew numbers didn't mean reliance on staff volunteering for overtime. Not sure that merging ASLEF and RMT would be a good idea..