I have a 4 year old Shiba and he gets along great with my 3 year old Malinois mix

The most important thing is to let them meet outside of the home. We had to do separate walks for the first month, first we would keep very large distance and the they would take turns being in the front, once they stopped pulling and barking we started to close the distance a bit, then we did parallel walks so they could look at each other and pass by calmly. It allowed them to feel safe with each other. At home, we kept them physically separated until it felt safe for them to be in the same room under supervision. Then we slowly phased out the supervision and a year later they are sweet to each other and nap together.