Seeing that you have absolutely nothing linking George Soros to these people, there is no universe in which your theory is the Occam's Razor of the caravan. It's pure, unadulterated speculation.
Welcome, so you see, two possible explanations:
1: Trump / the right is somehow behind the creation of a mob they cannot possibly control, in order to demonstrate how well they control it so that they can affect the mid-term election outcome via pro-right sentiment
2: Soros / the left who have done this before many times, is somehow behind the creation of a mob they know cannot possibly be controlled, in order to affect the mid-term election outcome via anti-right sentiment
If you count carefully option 1 includes 3 assumptions where option 2 only has 2. Occam's razor dictates therefore that option 2 is most likely.
Then we can move on and repeat the exercise with two options again:
1: see #2 above
2: a 14,000 strong crowd from different countries, for different reasons, magically formed an organised march toward the US border despite crossing many alternative countries on the way there. It is pure coincidence that it plays directly to the lefty agenda and is perfectly timed with the mid-terms. The people who have been handing out supplies and money to them on the way were also just being generous and have no agenda whatsoever other than wanting to help
Now count the assumptions ...