It does exhibit some strange behaviour. I'm using the modelbuilder to automate (as per example given, using iterate rasters then collect values to gather rasters) and on iterating through a folder containing rasters, it passes each one in turn, then reiterates, rather than iterating through the lot then passing the whole collection to the mosaic function. eg:
rast1
mosaic
rast1
rast2
mosaic
rast1
rast2
rast3
mosaic
...
rast1
rast2
rast3
rast4
rast5
...
rastN
mosaic
Now as i'm using the max operator, this does not affect output, simply makes the process incredibly slow. Especially when i have >100 rasters in each folder! I've checked output (against a manual mosaic) and it is including all the rasters, not missing any as some other people on other threads have found.
I have lots of folders so the point was to automate going through the set of folders, each containing many rasters.
I tried to batch the model and rather than mosaicing each set from each folder to a separate output, it mosaics them all together, rather than keeping each run of the model separate.
I tried to nest the model inside another model which iterated the folders containing each set of rasters and it fails (number of bands must match error) despite the child model working fine on it's own. The only thing being passed in being the input folder containing each set of rasters.
Am now doing each workspace individually. Thankfully not too many but still painful, especially having lost time to trying to get models to work...