If you have paid for full floating client licences, then you would have purchased 20x such licences, and hence would be allowed to operate 20 clients from this arrangement.
If you're not seeing this, then you should contact your local Tech Support branch to investigate further.
The clients would need to be configured to allow server floating licences of course.
If you have only purchased 10x full licences and the other 10x are redundant client licences, then you should only allow 10 clients to use these licences at any one time. However I don't believe there is a technical limitation here, I'm pretty sure the redundant client licence still appears as a standard client licence within the dongle / soft key licence information.
It is just a legal limitation, so if you were ever audited as to your licence usage, and it revealed you had more active clients than full purchased client licences then you would be in breach of the EULA and would likely have your licences revoked, and would be pursued for civil damages (sued for breach of contract / breach of copyright... whatever the vendor could get to stick).
Lead Control Systems Engineer for Alliance Automation (VIC).
All opinions are my own and do not represent the opinions or policies of my employer, or of my cat..