I can barely rationalise my selections to myself, nevermind to others! But I’ll give it a go… 
Why am I backing against Mullins? Pig-headedness, in short.
The Real Whacker has always looked a National type in my mind. I wouldn’t read a thing into his runs this season as this has been the plan since probably this time last year. He was entered in this last year after a half decent season, so I don’t really buy into the idea that this is a last roll of the dice with him. They obviously just fancied another go at a grade 1 so went for the Bowl instead. He was due to carry 11-4 off a mark of 159 last year, but now carries 10-9 off a mark of 151; that might be a sign of his decline, but it might also be an opportunity identified by connections. He might not be good enough against “hidden grade 1 horses”, but he’s 100/1 (even bigger if you shop around for bonuses) and I think he’s worth a go.
L’Homme Presse has been running consistently all season, one of which in a staying handicap off a mark of 162 so was clearly capable pf being competetive off a mark of 164 and his staying on fifth in the Gold Cup was a perfectly good performance to set him up for a National tilt. I actually really fancied him to run well.
At the end of the day the Grand National is a race that holds more sentimental value to me than any other race (or most other days/occasions) and there will always be a bit of heart ruling head with some selections. Half of the fun is making cases for anything with four legs.
What’s a tenner between friends anyway?