That being, with them lacking the Engineering research (forcing them to lose a turn when crossing rivers), me sending my units from Ambracia to be visible had them send their advancing army that was headed towards Sardica back. (It turned out Ambracia was never their target at all.) And then, when those units would hastily retreat, the immortals would then advance forward, back towards Sardica.
This is what in tower defense games would be referred to by that term. I went from having like 40 immortals to deal with down to 14 or so--they disappeared, retreating, once I captured Melitene. (And for good reason--with me controlling Melitene after a recent culture expansion, I controlled 20% of the world, thus, winning.)
The northern offensive was completely abandoned. I mean. I'm gonna face a southern offensive soon enough--but that'll be pathetically easy to deal with by the time the units make the long march down. Heck, I'm right on their tails, chasing them with a unit which is faster than they are, so quite frankly, they'll incur loss after loss retreating, while I advance forward.
I did end up sacrificing Thessalonika in order to pull this off. I also lost a few good units. A war elephant to the south (admittedly a scout). A swordsman to the north. But basically, the point I'm making is...not only did I win the game, I won the war in the game.
And the final result? A listed score of 2361...by far eclipsing whatever score I had as the Persians. Meaning, yes. I have cemented my place as the Carthaginians on the high scores, beating the challenge. It's so satisfying. I took the time in the endgame to note the destroyed cities I actually cared about.
Namely: there's a Roman city I wanted to capture but ended up sacking by default. That city was Aquileia. (There was also their final city which I missed the name of, oh well.) Maronea was a Macedonian city between Thessalonika and Byzantium which the Persians razed. Thermopylae is a city to the southern part of Greece which Persia destroyed. Corinth was the island city Persia destroyed and also reformed as Greece's current capital city. And Thebes is the other city I destroyed.
So RIP, cities destroyed, (various years they were founded) - (various years they were destroyed), may you rest in pieces and maybe eventually have a settlement replaced on top of your ruins.
By me, of course.