Terrible Reinhardt Conundrum

Personally, I would say do NOT run the -Atk. Go with ANY OTHER Reinhardt that does not have -Atk. Trust me, +Spd is better than -Atk.

Unfortunately they both suck, but if you can help it never use a -Atk Reinhardt as that is his best feature, so I would say use the +Spd one.

His speed is trash, but his attack is way more important, so go with plus speed.

If you run a mixed team to allow both Hone Cavalry and Lancina, he'd hit an impressive 38 speed, preventing a ton of doubles, and granting a nice amount of quads. Not that I suggest that.