The link below shows a theory I've worked out on how Mars evolved. It's pretty long so I'll give a summary of the ideas behind it.
Sprenke and Baker wrote a paper that showed a possible path of polar wander on Mars. They worked out this track by looking for elliptical craters, and it made this extremely long polar wander that went over half the planet.
I was thinking that it would be hard to explain why this polar wander should occur. For example it starts by heading towards Tharsis, which makes no sense as Tharsis would tend to be on the Equator with its weight.
So I developed the idea that this polar wander could be caused by the four main impacts, Utopia, Isidis, Argyre, and Hellas happening with a fairly long time between each impact. I haven't made any time assumptions here but all of this likely occured billions of years ago. Assuming Mars was relatively flat before then, each impact should change the balance of the planet.
This would occur by a large crater tending to go to a pole, which is the opposite of a big weight going to the Equator. So a big hole from a crater is like a negative weight that would start the pole moving. Also it is believed by many that the large mountains on Mars are caused by the shock waves of impacts going through Mars and forming a volcano on the other side. So initially the crater tends to move to the pole, then the volcano builds weight counteracting the crater and so the volcano and crater then move towards the Equator. This makes the pole go on a strange wander, and when you have this with 4 impacts you have a sequence which can explain much of the Martian terrain. That's because a pole carries a lot of ice and CO2 and thus erodes where it goes enormously. So you get this huge amount of ice and probably CO2 erosion on a planet where away from the polar wander it remains dry.
The start of this track by Sprenke and Baker fits in with the pole beginning nearly opposite the Utopia Crater which is quite large, then it moves northwards to be nearly opposite the Isidis Crater.
When the pole gets to under the current position of Valles Marineris the Argyre impact occurs. Because this would be at perhaps 80 degrees south latitude at the time the shock wave rips right through the pole, and explodes out of the ground. This would create a fracture around the edges that makes Olympus Mons and Arsia, Ascraeus, and Pavonis Mons. A reflection of this shock wave erupts out of the ground and creates Valles Marineris, and an annulus around the area in the same shape as the volcanoes. Both these are in the same shape and point directly at Argyre Crater. Alternatively the main shock wave might have formed Valles Marineris and the reflection off the mantle the Mons.
At the same time the shock wave also goes down through the core and creates Elysium Mons, Alba Tholus, and Hecates Tholus. This impact might have blown away a lot of the frozen ice and CO2 from the pole leaving a dry planet with little atmosphere. Then the pole starts moving eastwards and as it does it tries to reform, sending huge amounts of water into the area around Margaritifer Sinus creating the flood channels.
As Tharsis and Olympus Mons grow this pushes the pole eastwards as the Mons tend to bring their weight to the Equator. So the pole moves almost exactly along the edge of the dichotomy boundary.
Putting such a huge amount of water, ice, and CO2 along this track would cut out the cliffs of the boundary and move lots of water north. This water would create an ocean and ice sheet, and this water seeps into the ground liberating CO2 and ice deposits into it, which makes the land drop in elevation creating the Northern Lowlands.
Eventually the pole gets to Meridiani Planum where there is a huge ice deposit today, and one 180 degrees opposite it. Tharsis has got near the Equator and Elysium Mons which is forming strives to also be on the Equator, so these hold the pole between them in a relatively stable position.
At this point the magnetic field of Mars is probably still active as there are signs of rotational poles along this track. Then the Hellas impact occurs which sends the pole downwards to the edge of the Hellas Crater, while Alba Patera forms opposite it. The force of the impact probably destroys the magnetic field of the core like a hammer hitting a magnet. The heat from the volcanoes warms some of the ice on the Northern Lowlands and creates a flat lowered area all the way up to the current North Pole.
Eventually Alba Patera grows large enough to counterbalance the negative mass of the Hellas Crater and the pole starts to move again. By this time the volcanoes have cooled and the air starts to freeze and the ice goes to the poles. This vacates the ice off the Northern Lowlands and soil on top of it settles obscuring many craters. This creates a huge negative mass centered on the North Pole so the pole moves to its current position.

http://www.harmakhis.org/marshistory.htm