What length rod for what purpose

Can anybody shed some light on what different lengths and actions are
designed for? For example, fill in the blanks with all that apply (e.g.,
crankbaits, worm, spinnerbaits, topwater, etc):

6' med = __________
6'6" med hvy = _________
6'6" med = __________
7' med = ___________
7'6" med hvy = ___________

That seems like a reasonable sampling. What do you say? I am just trying
to figure out what to do with all those rods I bought on sale at BPS.
Mostly trigger style rods with baitcasters.

Thanks.

K