What do you more experienced soccer bettors use as a rule of thumb in finding equivalent value between 2 soccer totals using split lines.

For example:

For Team A/B under 2.5 is -110

What would you consider the equivalent price for the line under 2, 2.5?

or A/B over 3 is +110 what do you consider equal in over 2.5, 3?

Does this estimate change if there is a heavy favorite vs. an equal match?

Any input would be appreciated...