You can put a skilled player as first player and a less skilled player as second player and the less skilled player will win. It doesn't need fine tuning, it needs reimagining from the ground up. Progressive scoring and removing Retreat would be good for Infinity in general.
Given I have won a few times as first player, skill level gap is a factor, how big of a gap I agree is open to debate, as are faction matchups. I disagree on retreat, retreat is what makes most games not an effort to table your opponent as soon as possible and play the actual mission.
I've played enough without it to know that that isn't true. A skilled player can make it so if you try to take out his army you won't have enough time to score points before the game ends.
Retreat as a rule is not necessary to make it so the game becomes about killing your opponent's army and nothing else, because in most missions that doesn't score you points, doing the mission objective does. Mainly Retreat punishes people who play against an opponent who can score points early and then put their dudes in the way of an objective. I've also seen Retreat scam lists where people purposefully take a dive on army points to win round 2. Overall, it's a clumsy attempt at a rubberbanding mechanic that the game would be better off without, but there's so many other issues with mission design that it's a debate as to the best place to start. Progressive scoring, however, would be a much better idea.
Ill start by saying, not bringing maximum possible points should be an offence and people should feel ashamed of even trying it. What you say is fair, what Retreat as a game mechanism tries to do is penalize players who make a list with the sole purpose to wipe out the enemy and then progress unopposed to score the next two rounds. it is not a perfect solution, I had a game recently that I somehow managed to keep my opponent from retreating for one point, but it is a solution to this problem. I am open to discussion if this is really a problem or any other suggestions or solutions to this problem.
They've had plenty of time to change that rule, and they haven't. Instead the Retreat rule has been spread to every mission they can, which imo is a mistake. The game straight up doesn't need it. The fact that people try to dance around the retreat threshold makes it a problem; it's gamey and smacks of someone being on the receiving end of a crippling strike top of 1 and making a blanket rule to "prevent" it that is poorly conceived and just another thing for clever players to exploit. It's still very much possible to cripple your opponent turn 1; as it stands the rule just allows for weird scam play, and in tournament tiebreakers, tends to punish players who play factions that don't have ways to evade past enemy overwatchers to get to objectives (such as PanO). In predictable Infinity fashion, it rewards factions like Tohaa and Nomads the most.
I will concede that there is no rule forcing players to allocate the maximum allowed army points when making their list, for me its something I learned people may think of doing and actually do this year with Reinforcements.