Hey there. Question is if this is primary or secondary?
If it's primary, you actually should have even more space. A good rule of thumb is to have at least 20% head space. So for a 5 gal batch should have at least 1 gal head space.
If it's secondary, then yes you want as little headspace as possible. But the reason you want it to have less head space is to avoid oxidation. Moving it into another vessel would only risk more oxidation. One way to avoid this if you have a kegging set up is to just fill the vessel with CO2 before and after you fill it. Hope this helps.
- ISM NRP