Interesting...though if we take this tack we must remember the laws of the Chronoverse: nothing happens until it happens, and as such the tabs found in the various timeframes are not related to the actions of Crono and company. In fact, the number of tabs and their locations should be reduced immensely until the fall of Zeal when you begin bringing ingredients to the Tab Creator, and then and only then will tabs begin to appear in locations where they might once have been. After all, we've been introducing many Chrono Compendium theories as fact into this, so we definitely need to stick with it in that regard.
Besides...lessening the number of tabs available so readily across the eras to the later parts of the game will help balance the game further.