Welcome to the 'Yard.

The Scrapper 5 is an awesome blade. Not sure how it would go as a defence knife against dogs, as I'm not sure how you scientifically attack a dog with a knife.

I guess if you need to stab deep (.e.g. need to penetrate into a deep canine chest) it may not be the best choice due to the blade length and it similarly would not be so good for a chopping attacks on the CNS/circulatory system (e.g. chopping of a head or a limb ).

However if stabbing to 3-5" and slashing attacks are acceptable then I'd say it would do fine.
I'd have no fear about failure and SR101 and INFI both take and hole fine edges.

The LE is Satin INFI, so you won't need to worry about coating and food and is pretty good re corrosion resistance - pretty much the premier Bussekin steel.
And in my mind the S5 has mighty pretty lines.
So if you decide the S5 design is suitable for your needs, then you chose the right time to join the 'Yard!