The cut-off is usually 82/90. If you are between 82 and 95/90, then that is in the instructional zone, and considered to be normal. If you are below 82, then tasks would be expected to be somewhat difficult. If you are below 67, then they would be expected to be quite challenging. Below 24, extremely difficult. Below 3, unrealistic. Above 95, it's probably on the easy side. In school settings, a lot of evaluators use 70 as the broad cutoff (you can compare it to getting a C-/D when most kids are getting an A-/B+, so barely passing, thus not really keeping up with grade-level expectations).
So he has three scores in the moderately difficult range:
Verbal Ability 81/90
Cog Efficiency 82/90
Visual Matching 78/90
Two of them are clusters, and one is a subtest, which feeds into the second cluster score (meaning they stem from the same weakness). Cognitive Efficiency and Visual Matching are both reflections of visual-motor speed, and will most definitely be impacted by fine-motor, perceptual-motor, and handwriting skills.
The remaining subtests that you've pointed out would not normally warrant further investigation, as they are well within the average range, except in the context of being significantly different from his other, higher subtest scores.
