additional tenant that adding to the existing lease

[Vicheka Chres]

Hello BP, 

I'm renting out this single family home to (currently) five individual tenants. One of them vouch for the additional tenant. I modified the lease to add the last tenant move-in date to Nov 1st but I haven't yet receive everyone's signature. So far I got three out of six signatures. Would this be a problem? If so, do you any suggestions of how I should fix this? 

Any advices and suggestions are appreciated. 

Thank you :)