You could easily switch that ratio of 5:1 to 1:5 being applied to the number of states being campaigned in since lower population states would be ignored in favor of high density populations. Heck, pick the 10 most populated states in the country to campaign in and don't worry about the rest.
It's all a numbers game.
Its a Numbers Game and your losing it.
Smaller States are Smaller they cost less to Campaign and are cheaper to improve.
Meaning they offer fairly good chances to convince them and even impress by fullfilling promises with them which can grant large Majorities.
Bigger States offer more Votes. But in exchange its almost impossible to get large margins over the other Parties because different regions within that State have to be addressed independently.
1% in a Big State wont make up 10% in a Smaller State.
And when each Vote Counts the Big States might actually have less influence than you think.
Because its not like one Party will turn em around to 100%
So the Party which manages to get large Turnouts in several Smaller States will have an advantage over the Party which only Focusses on winning a few Big States.
If each Vote Counts. The Size of States does not matter that much.
Because wether you tour 10 Cities in a Big State or 10 Cities in 10 different Small States doesnt matter.