...or maybe the dependencies for the packages in smecontribs (namely, php5?-php-pecl-zip) can also be added to smecontribs.
I have intended to avoid to import the whole remi-safe repo in smecontribs and just made it easier for people only installing the base php requirement of the contrib.
The wiki page needs to be updated for this as i was still in the stage of seeing if it was working clearly before documenting it. So there eould be two way to update, either minimal install all in smecontribs, or custom install which will need remi-safe enabled, but i need to search for other deprndencies from epel. Only two hands there.
I must made a clear warning here, and i have seen that modification of the wiki should be done accordingly : remi repo should not be used or configured on your server because it will break updates by replacing base rpm. With epel a similar concern is present you should not update with it enabled unless you update a specific rpm. That is why contribs how to should avoid to invite people to use epel to install a rpm. Instead it should be imported in smecontribs. If there we will be able to push update, if not either you will remain with a old unsecure rpm or migt suffer trying to update it.
For remi you could and should use remi-safe which is designed to not conflicts with centos rpm.