Most of my favorite cameras have slower shutters than your 1/400. My Moskva-5 has 1/250 max, my Wirgin Auta 1/100, my Pony 135 1/300, Reflex II 1/300, both plate cameras 1/200, and I have a number of simpler cameras fixed at "slow".

I don't find it limiting; I routinely shoot ISO 400 films in most of these (though my Speedex Jr. requires me to pull to EI 200 to avoid gross overexposure in full sun). No, I can't shoot at EI 1600 in daylight, except with my Spotmatic -- but I don't need or want to, in general. I suppose I could always put on my 3-stop red filter and pretend it's ND if, for some reason, I were shooting Tri-X for later Diafine treatment. Even if you load Delta 3200, it's really an ISO 800 film that pushes exceptionally well...