Unfortunately, that isn't likely to happen. Netanyahu has, to date, handled Trump deftly and Rubio's current presence in Israel seems to be aimed at offering support to the ground offensive, not opposition. I honestly have no idea what kind of backlash it would take to shake U.S. support for this genocide.
And look at Israel vs Hezbollah--Hezbollah makes little use of human shield tactics, casualties run in the ballpark of 90% combatant. Same force, same type of opponent, what's the difference in Gaza? Hamas makes very heavy use of human shield tactics and worse. We see 30-50% combatants. That implies that the majority of the deaths are because of Hamas.
Why would the military in countries hostile to Israel provide Israel with advice or plans on defeating their enemies?