On this page: https://liquid.net/ If you click "Member Details", federation members are all listed, and there is the picture of each member on the board (among which the board deciding of membership changes in the federation): https://liquid.net/governance
So I think we can fairly say the federation members are public.
However it looks like the block-signers subset is not identified. And I didn't find this info on mempool.space either, whereas for Bitcoin we know which pool created a block. And since the federation members are dynamic and can apparently leave at any time, the web page could be outdated at the moment we speak. I don't know how often the page is updated.
There is a difference between liquid members and liquid functionary members. It's intentionally confusing. The public list is are just partners allowed to peg out.
The people running the network are nowhere on there to be seen and they're the "guardians" in liquid's case.
I just checked again and I think what you call guardian is what on the Liquid network is called block-signers, like the miners on Bitcoin. And the watchmen are those who are responsible for managing bitcoins on a multisig. I don't think there is confusion about this.
However indeed the list of block-signers and watchmen, although I assume is in the list of functionaries looks like hidden. I will ask on their community group.
The reason why apparently is to avoid cases like Tornado cash or Samurai wallet. Which I can understand.
no the list is not public, the functionary operators of the federation can decide for themselves whether to be public about it, for example Nym is a public operator.
watchmen and block signers are currently the same 15 set