Good point hikermor, and to that point I have spoken to someone who hikes the trail regularly. He mentioned the same things you did, his exact words were:

On trails that aren't trimmed back well, ponchos can be a pain because they catch on everything. On well maintained wide trails, they provide good coverage and ventilation (as long as it isn't very windy).

He added that on the trail we'll be hiking in April ...

You should be fine with a poncho ...

Doing more research but a poncho appears to be a promising option, with the pants maybe as backup if it gets bad