What I'm saying is this:
If a team manages only to get 2 shots in a period (you yourself said it probably happens quite often, yup) so can it really be a more impressive thing that instead of 20 minutes that feat keeps for 40 minutes more? It could include like post shots or close misses and lots of blocks.
However to shoot 30 times in a period the first thing it requires to happen is that the specific team must have the puck for a long time in that period, not only that it requires that they keep it in the offensive zone, and then it requires that the puck is shot at the goalie. Not to forget that the team has a big chance of losing control of the puck after each shot, if it goes to faceoff the team must win the puck back again.
Also if a team only manages 6 shots, that can include most of this. Can have offensive zone time a lot without getting shots away, can have shots taken but that are blocked etc..
30 shots in 1 period is way more impressive feat.
And about keeping up the pace was not my point, the point was that if you mathematicly calculate then it suggests that 90 shots per game is more impressive and definitely rarer than 2 shots per period. Pure math