of course one can compare them the way you mentioned - to take it even further down the line of extreme examples, one can similarly compare Tom & Jerry the movie and Shrek with the Godfather.

What I meant was that there was rather limited to no basis for a meaningful comparison.
The Godfather is fiction in itself but depicts real life as close as Puso/Coppola could get w/o ending up with a horse's head in their bedsheets ... actually, iirc, Puso did get death threats at the time. The LOTR and Dark knight, on the other hand, are so far from reality that you can put a unicorn in there and it's not gonna feel out of place ... on second thought, iirc, there was one in LOTR

. Any character development is thus taking place in drastically different environments/circumstances - in one case a harsh, real-life like story where there is little to nothing to feel good about, in the other a brother's Grimm on steroids, good-beats-evil, feel-good all the way plot closely following a comic/children's book. Sure there would be some character development in both cases but how do you even begin to compare those in the first place? On what basis - which character faster realizes that being good is ... good and being bad is ... bad, while going thru the most ridiculously unrealistic situations?
Not to mention that LOTR and the likes are heavily based on special effects, which is such a widely and also overused tactic to compensate for the lack of or big shortcomings in the plot of the movie. take away the special, fairy-tale effects from those movies and what do you have left in the end - Hansel and Gretel in PG13 form. Do that to a movie like the GF and you have the whole movie left. So, how do you compare "strength" of a movie here? By which movie takes H. and G. back home using the safest and shortest path thru the forest?