This battle has never been 1v1 and never will be.was purely a compassion of military power only, nothing else.
it was a pure who would win 1v1 Israel or Iran based on their military capability.
Israel 10/10 times
The massive gamble Israel are taking is not on if it will be 1v1, it's on how many countries join Iran and how strongly they do it.
Israel will have limited US support, I'm guessing air defences. Will the US risk flying planes near Iran, or putting their ships within drone/missile range of the Iranian mainland while flying offensive sorties? I doubt it.
Russia is the biggest wildcard. Nobody knows how much support they can, or would be willing, to offer Iran from within Syria. If they provide a lot, Israel are in all sorts of trouble. Russia could enforce a no-fly zone over Syria for Israel/USA planes and also facilitate Iran launching from within Syria and Lebanon. Turkey could also do the same thing.
Jordan is the other unknown. Likely to stay as neutral as possible. Their population wants them to join Iran, their leaders would want to join the US (Israel). Doubt they'll contribute militarily, but what they permit over their airspace will be interesting.