They took the wagon and the plow from the upper floors of the museum, they had to bring down the stairs, and then across the glass floor that had been damaged from a zombie + stone block landing on it in an earlier scene.
The seeds they took, I get it, that's an organic that can't be created, or probably sourced from anywhere else. A wagon though? Easily built, even from an old car/truck chassis - and at the Saviors joint, they've got Eugene and what appears to be a forge, they could reproduce a simple plow using a book - plus with all that ground covered they didn't pass a single sports shop? A boating/fishing store? Any number of places to get a modern canoe? Isn't all that stuff antique and probably fragile?
The whole idea of risking lives over items that would be easy to source from other locations (and better/newer versions), or build, just seemed a little kooky. The set piece itself was cool, it just doesn't stand up to any scrutiny - and come on horse-dude, you can't slip up and cut a horse loose without just stumbling into ONE zombie? How did you survive this long ... ?