Let's say the Liberal conspiracy theory that Poilievre asked Trump to endorse the Liberals is true. If Poilievre has that much control over Trump, that's good for Canada because he can control him to leave Canada alone like a puppet master.

Either

1. Trump genuinely dislikes Poilievre's negative comments toward him and thinks the Liberals will be easier to push around. That means Poilievre is tougher to defend Canada with.
2. The Liberal conspiracy theory that Poilievre asked Trump to say he endorses the Liberals on TV is true. That means Poilievre controls Trump and can play him like a puppet master.

In both situations, Poilievre is better suited to stop Trump.