When you're gluing two baffles together, you don't need a lot of glue. If it's sliding around, it's a sign that there's too much. A very thin layer should do. What you lack in a heavy glue layer is more than made up for by surface area.Imagine a butt joint between two pieces of 3/4" MDF. The joint is 4" long. Once that glue dries, it's strong enough that you can't break it apart with our hands. And there's only 3 sqr inch of gluing surface in that joint! On your baffle, it'll have over 400 sqr inch of surface area for bonding.
What I would do is water down the wood glue and brush it on with a 3" brush. The water will let you apply a smooth even coat and increase dry time to let you cover the entire area. If you're still worry about sliding, take a carpet knife and score diamond patterns across the entire surface of one of the baffles. The grooves will let the glue squeeze out and keep the two pieces from floating.
Gar.