Hi,
I have applied through an agent and have 2 people helping financially. I have a sponsor for my tuition fees and a friend who has invited me to stay with her and her family covering all living and travelling expenses.
All I did was I got letters from them stating that they are helping and got bank statements from my sponsor to prove that he is able to in fact help with my tuition as well as still be able to support himself.
I think at the end of the day, as long as you have all the supporting documents in place it should be fine if you have more than one person helping.