It's important for player's to practice passing tough serves in practice so they will be prepared for when they see tough serves in a match.
Serve floaters in practice so your team can practice passing a ball that floats.
Not only does your team get the benefit of learning to serve tougher, but your team will also get the benefit of passing tougher serves.
If they never see a tough serve, then they won't be able to pass it when it happens in a real match.
The following drill helps teams to learn to pass the float serve.