English adjectives ending in -ic or -ical are a real problem. There is no
system in it and if one looks more carefully into this matter one finds
various sorts of types. One might say in this matter language has gone wild.
PS Well, to add some examples:
There is only one adjective in -ical. Of the same type impractical,
theoretical, hypothetical.These adjectives have no noun of the type *practic etc.
There is the noun the logic. The adj is logical. There is no adj *logic.
Type economical + economic
Both adjectives exist with different meaning, The normal adj is economic.
economical means a good ratio between cost and result.
Type classic + classical
There is the noun "a classic" and both adjectives. The use is difficult.
I made a note for myself: Look up the dictionary when you have to use one of these adjectives.
This is no extensive study. This is only meant to show that adjectives in -ic/ical
are a problem.