Cloudbase in METARs

[MichaelJP59]

FEW005 SCT007 BKN009

This is from a METAR at LBA/EGNM today.

I believe they only detail the first 3 layers of cloud. But how can an observer at the field possibly come up with a sensible oktant estimate for 3 layers of cloud 200 feet apart as listed above?

Also, how would I know from that whether it is overcast above 900 feet? As this would obviously make a VFR flight impossible.

Thanks for any help.