IMHO, if you could find a solid shaft clip as in #3, it would be the way to go - IF you are using flat leather.
Another opinion I have has to do with the strength of the leather or whatever material the leash is made of. If it is a flat lead, then putting it through a round eye is going to wear at the edges of the leash and it will definitely shorten the life of the leash. You need to be prepared to inspect that leash at every opportunity and scrap it when the wear gets to a 15-20% level. You may want to think about looking for a square eye.
If you are using a braided lead and have 'wear leather' on the inside of the clip loop, you have better security. A 10-12 str 'roo braid with two or three paracord cores, back braided into the leash itself, will provide you with an enormous amount of strength.
I don't have a Rott, but I have 5 GSDs that are protection trained and I work them at least 3x a week. I use a 10 str 'roo braid as described above. I've also got a 6 str 'roo braid with a French Scissor Clip by Herm Spenger. I have wear leather on that one and have replace the wear leather a couple of times. The clip is deceptively strong and is favored by law enforcement and some military applications. My biggest reservation is the loop. It just seems too small and too sharp. After all, we don't want our "sweet things" getting loose at the wrong moment.