The answer always is: "It depends."
The basic rule is to fair out from your hole/crack/seam in a 12:1 width; so for a 1" deep hole you would fair out 12" and replace with new laminate.
I did my port side deck recore last year by re-gluing the top skin down. I did my stbd side deck recore this spring and re-laid new laminate for the top skin, which I think works better leaving no seam to fill.
The cloth that made building up the new laminate easy was a biaxial cloth I got from fiberglasssite.com - but I had to buy something like 10 yards of material, which is more than I need. I think that this biaxial cloth builds up close to 1/16" per layer which is a lot.
Here are some pics of my first re-core attempt where I re-used the top skin: 2013, May 2nd. Re-core work party. | Odalisque
PS: my port deck looks a lot like your pictures. I'm moving on to painting and trying to finish up this job.