I understand the point you mentioned, but I'm uncleared about one point mentioned below.
Generally the data pages will get load, whenever we refer that particular data page right. So my point is, some user has to be go that particular place (referenced place in case or in dashboard) where data page has been used to load the data right. In that particular time the node level data page can use the, this particular user's or requester access group right.
When some one intervention or referenced place to be launch, required to load the data from data page, then what is the need to have separate access group for Node level data page. It can use the same requester access group right ?
Generally rule resolution will works on access group to find load activity to load data on to data page. And generally Data page will load data only when it referenced in some place. that time it can consume that particular requester access group to load data, there no problem system can use that. But the point of or the utility of data page is to load one time and share the data to all the requesters connected to particular node.
If it use every requester access group, then it has to load for every requester. Then it loose the concept of Node level Data page.
So for this reason only we have maintain a separate access group for node level data page to invoke load activity to load the data and it can be shared between all the requesters connected to that particular node.
Thanks, it can be helpful to others who has a confusion with this point.