…Initial evidence suggests that, in a rematch between Biden and Trump, a No Labels and/or West campaign could pull marginal support from Biden and subtly shift the election toward Trump. Whether this would actually make for a potential spoiler, though, is a different question: History — and common sense — suggest that these possible third-party candidates would be most likely to affect the outcome if the overall race were close. But in our deeply divided political era, close elections have been the norm, which makes a spoiler candidacy a live possibility…
In practice it doesn’t work that way. There’s as much chance a Green elevation is going to work against Trump. People in Republican states aren’t going to vote for Biden, but they might be persuaded to vote for Green candidates over Earth conservation issues. Farmers and hunters can usually see green problems despite not being able to see progressive issues.
Some of the greatest conservationists in the world have come from hunting groups that have become disillusioned by the loss of game to aggressive corporations and destructive hunting practices. Similarly farmers see the breakdown of the ecosystem.
None of this needs to involve liberal and Democrat viewpoints.
Per OP, the concern is more about a No Labels-funded candidate. It’s Perot all over again. Clinton won by 6%. Perot got 20%
In other words… in practice, it worked that way in recent history
Generally Libertarian party voters have more overlap with Republicans, and Green party voters have more overlap with Democrats. Both run in most elections.