1. Offset Attach Point: maybe your problem could be solved by offsetting the track point instead of creating a new Tracker? you could track everything with the same tracker and track points and if the problem is that the feature region is obscured or goes off screen you could change the feature and search region and keep the attach point by pressing Alt as you drag. this way you don't need to use different Trackers. more about this method below.
2. Nulls: if the problem is that one motion track continues another there is always the option to set one motion data to a null and the other motion data to another null and attach one null to the other so the motion continues seamlessly
3. TrackerViz: if you still need to combine different track points that were tracked separately there is this script for averaging trackers.
about offsetting the attach point this is from the link I sent you.:
Set the attach point offset
The attach point is where the target layer or effect control point will be placed. The default attach point position is in the center of the feature region. You can move the attach point to offset the position of the target relative to the position of the tracked feature by dragging the attach point in the Layer panel before tracking.
For example, to animate a cloud above a person’s head, position the feature region on the head and move the attach point above the head. If you left the attach point centered in the feature region, the cloud would be attached to that point and would obscure the head.Attach point centered in feature regionAttach point offset from feature region
I will also recommend this course: