I have never met a soap I could not lather. I even lathered Lava pumice bar soap for the fun of it.
Here's how I do it.

I shake out my brush pretty dry and load like mad for 30 sec to a full min. I then smear the pasty soap on my face. It goes on thick, sometimes I need to dip the brush tips in water to get it to spread on my face right. After my face is loaded with soap I dip my brush tips and work the wet brush into the soap paste on my face repeating the water dip until I get a good lather. It takes at most 2 min.

I've done it with bar soap, tallow soap, preshave soap, hotel room bars, even Lava bar soap. I've even done it with new Williams.