Dear Wizard in the Forest,
the teaching sequence of both is different.
In Theravada one normally starts to run on the feet of wisdom, while (the other leg) compassion is at the beginning, (let me use the word without seeing it negativ please) a crutch. These crutch are the Silas (while they are not developed, as the wisdom is not rippen enough). The interaction of both are reaching to more wisdom and with it a second leg grows. With both legs you are able to walk and do not fall. That is the point I guess you will not see much differences between both any more.
In Mahayana one normally starts to run on the leg of compassion, while (the other leg) wisdom is also a crutch at the beginning. With its limits of "compassion" by missing wisdom, the second leg starts to grow. Just in the same way, but contrariwise.
In Theravada the three pillows are:
Sila --- Sati --- Panna
It is the same in Mahayana:
Compassion - Mindfullness - Wisdom
Sila is an act of Compassion, even for one self.
Mindfulness keeps sure that both are growing equal as they are developed a little.
In Theravada the most commune motivation is the own liberation. (as it was taught by the Buddha)
In Mahayana is the most commune motivation to liberate all. (as it was shown by the Buddha)
You could call Theravada as the operating regiment (defensive), while the pioneer regiment is Mahayana (offensive) and they are interacting in all levels. The more people are walking (having compassion with those who like a cars) the more others are able to use cars (to transport those who are need it fast).
perfect wheel of the Dhamma, you just need to take that care what looks safety for you. No need to worry, as one sees that it goes on the right way, he is also able to change the stile of moving on.
Walking is safe and even very beautiful. Who would waste time to discuss, which car. If you start to walk, you have already some kilometers in the right direction. There will also come some cars along. You can choose a change on the way.
Some may discuss for month, years and lifetimes. Should we take the bus, rent a car, buy a motorbike, maybe a train, no this driver does not look serious... Just walk on, step by step.
Buddha walked his whole lifetime, never taking a vehicle, after he left his home, and even so he was able to bring so many to the aim.
with loving kindness and joy
Just that! *smile*
BUT! it is important to become a real Buddhist first. Like Punna did: Nate sante baram sokham _()_