Yes, the lvl 91 14.96" guns quadruples on the front slots. On the rear R-slots, I'd only put Hedgehogs. At the moment, they are not that useful, as there are no subs ingame. But after the event...
I see most Richelieus without AA, but if you're good at it, put the standard French AA guns on the T-slots (the lvl 20 3.5" doubles, they are excellent).