Targaryen Dragons :
The wording of your question is mostly what has me stumped but I will try and answer it.
The team rating that is displayed beside each team is based on the average rating of all the players in their squad, whether they play with them or not, so the players who are actually used may be much stronger than the average rating given. The third part is the allocation of those points, one teams number 12 might be rated 200 while the other teams 12 might be only 150, so you'd expect the first team to have the advantage, but if those points are allocated to skills not needed (ie scrum or line out) and the second team has allocated wisely, then it is the second team that has the advantage, so when scouting opponents you nned to check the individual skills of the players, not team average
This. Although I have now come to the conclusion that when all the key skills are maxed on both teams, then the star ratings come into play as a deciding factor between the two.
However, a very good strat that is, in particular, well suited to beating that particular teams is more often than not the final decisive factor.