MaizieD your first sentence makes the point - anyone can set up an APPG and it has already been suggested that there needs to be more control over who finances them as some of them are effectively being used by companies/organisations that support them as mouth pieces, because they will wine and dine and feed information or hide or play down information to memebers to shape their decisions - and if you really think that isn't done already, you are being very naive.
Now think of that in terms of another foreign country, which we know already induges in commercial espionage, cyber disruption and subterfuge and it must be easy to see how the person who pays the money and feeds a lot of information to members of the APPG and uses it to extend their own political networks can use it to influence how members of the APPG and through them others . Remember MPS are ordinary people, some are diligent, work hartd themselves, employ good reearchers and interns and reach their own conclusions. Others are lazy and will just depend on what info is at hand to make decisions, and if someone on an APPAG passes information on to them, that is influenced by the Chinese government and its very charming 'independent' Chinese financer, isn't it easy to reach conclusions on that information.
You know the way you are querying this Maizie makes me think you may be part of the network.