I think every team that has qualified for the semi-finals in the Copa America is strong. But Argentina vs Canada match will not be so competitive because Canada is a normal team compared to Argentina. Argentina is a strong team so they can easily win against Canada and they will go to the final. On the other hand, Uruguay vs Colombia will be the most intense of these two matches as both the teams are strong enough so there will be a lot of excitement in the game here. However, Uruguay are more likely to win and Colombia look like they can beat them, as Uruguay beat Brazil to reach the semi-finals, so will definitely play well against Colombia in order to reach the final.
Currently the Copa has entered the semifinal round and 4 countries are ready to show their quality and abilities in order to qualify for the final round of the Copa, the Argentina vs Canada match will of course be a replay of the previous match in Group A, Argentina and Canada are the two teams who were previously in the same group so I think the final result in the semifinal match will not be much different from the previous result they got, so far Canada is a debutant team that was able to surprise us because they were able to beat Venezuela and qualify for the current semifinal round, however Seeing that Argentina is their current opponent, of course it is unlikely that Canada will be able to reach the final round.
In other more interesting matches, of course we will see two fairly evenly matched teams fighting for a place in the final later, Uruguay, who succeeded in destroying Brazil And of course has huge hopes and motivation to reach the final, but Colombia also has a perfect journey until the semifinals, of course they won't be an easy opponent for uruguay.
Compared to the match between Argentina and Canada, I think the match between Uruguay vs Colombia will be a more interesting match because the strengths of the two teams are very balanced.