Understanding of "et al"

[Tony Thompson]

So I've managed to grab 4 appointments this week (excited beyond belief). 3 of those according to the tax assessor's site are owned by "name, et. al." the question is for the contract to be valid are the signatures of the others required, or is the signature of the specifically named individual sufficient?
My lawyer has said "I don't know enough about what you are doing to assist you with this venture" as he hands me back my retainer check back! Any thoughts or opinions are greatly appreciated!
Thanks