I would argue that Britain is indeed a bad example for us because Britain has a first past the post electoral system. We have a pure proportional representation system and we never get the opportunity at national level to vote for a person, only for a party. Political parties and their bosses in our system are potentially extraordinarily and (I would argue, dangerously) powerful. If there are no guidelines for how such a party should operate, it basically serves as an invitation for corruption and the subversion of democracy.
In a first past the post system the local party branch has a big say into who the candidate would be, thus watering down the power of the central party. But in a list system of proportional representation in the absence of any regulation the party leader(s) can easily "stuff" the election list with favoured and loyal candidates, thus ensuring a compliant and possibly corrupt Parliament.
And in the absence of basic rules about the funding and accounting of political parties, the Chancellor House kind of shenanigans becomes inevitable. Then parties like the ANC and the DA can take money from anyone and never have to inform the electorate about it. They also never have to produce audited financial statements, despite receiving millions of our taxpayers money.
Surely this is untenable? One can, of course, argue about the level of regulation and I would not be in favour of legislation that attempts to micro-manage a political party. But requiring political parties to conform to basic requirements of internal democracy and basic transparency in party funding can surely only be a good thing for democracy.