how to match pen tool and paintbrush tool stroke size?

Hi, I'm new to Illustrator so bear with me.

I can't seem to get it to work, I'm trying to use both pen and brush with the same size but the only workaround I can do is to match it manually

(pen line is the smaller one)

both lines use the same profile, I may miss or have done something the wrong way here, but I would like to know how to match the stroke size automatically somehow.

Thanks in advance!