Learned with Lexi I couldn't let them run and play together. Luke has a tendency to run full speed and ram with his chest, or trip another dog up while they are running full speed. I had hoped he would outgrow it but he didn't, it is simply a way he plays.
Since Luke is such a rough dog I haven't let him interact with Lexi for a while or with Ace at all. Too concerned he would damage their growth plates or break their necks by flipping them.
I tried to introduce them and since both were wanting to act out decided to do their introductions under obedience drills.
Put them both in heel together, and took them for a mile walk. Since I plan on having them pulling a cart together I thought it would be a good way to get them used to working side by side. I had them do sits and downs together at intervals. I was surprised at how focused they were on the drills.
I did side steps, turn arounds, one eighty's, Did exceptionally well. I was surprised as Luke has never walked in heel with another dog. Ace has with Lexi. Almost as if they were trying to compete to see who could do the best.
The first half I had Luke on the outside and the last half mile I switched them up. Ace being on the outside challenged him becuase he had to watch Luke to cue what he was going to do since he is shorter than Luke and couldn't see my leg.
Working them together also saved quiet a bit of time. I only walked 2 miles insead of 3.