Yeah, you've exactly nailed the issue. Cavs need two-way players, not 1-dimensional guys.
My all-in solution is to use Love to get Butler and Kyrie to get PG13, and force them to throw Teague in there too (maybe giving up Shump and JR in the trades as well). That leaves you with:
Teague
Butler
PG13
Lebron
TT
That's a starting lineup that could compete. PG13 as a 2nd option, Butler as a 3rd option, Teague as a 4th option....that's plenty of firepower for a contender. And on defense they'd be lights-out, able to guard anything and switch everyone (except big centers).
Ask for Rondo too in the Bulls trade, and you have:
Rondo
Felder or Liggins
Korver
Frye or Derrick Williams
Tavares
Which is a much more balanced 2nd unit than they had this year, because you have someone who can actually run an offense for the shooters without Lebron on the floor, along with enough defenders to not fall apart on that end. Put Frye at center with Korver and Felder in for an offense-heavy lineup, or Liggins/D-Will in at the same time for a defense-heavy lineup, or any balance you want.