PPT Slide
If these clouds are roughly spherical, they will weigh around a million solar masses, and the cluster will contain at least a million of them. They are probably gathered into 100 kpc sized concentrations, which may be galaxy halos or protogalaxies.
The clouds are probably not stable: the mean time to collide is of order one hundred million years: when they collide, if the gas forms stars, the star formation rate should be around 0.1 solar masses per year: just about detectable with modern techniques. These clouds, when photoionised, could be responsible for the lumpy Ly-alpha nebulae seen around Blob 1 and many high redshift radio galaxies.