Apart from the fact that two entirely different teams worked on the movies, Simba's Pride has more in common with the first movie than might meet the eye:
Sarabi's voice actress died shortly after the first movie, so Sarabi was left out probably due to a combination of respect for the dead as well as the inability to find another reasonable voice for her.
There is in fact a re-used song straight from the first movie: "He Lives in You". Okay, it's not really true, as that song was written right after the end of production for The Lion King, and is found on the Rhythm of the Pride Lands CD. But for all goods and purposes, "He Lives in You" is a Lion King 1 song, and not a SP song.
/Elitism
And the score of SP is also heavily influenced by the first movie. Sure, it doesn't even come close, but the background music gave me too many feelings of deja vu of the first movie for it to be a coincidence. On that subject matter, "We Are One" also copies that African/Western Pop combination for songs from the first movie, where a song is written as a Western pop song, but to make it fit better, it is given specially fit African vocals (provided by Lebo M) which gives the songs from the first movie that great feel.
As for Timon and Pumbaa's jungle: Was it really needed in Simba's Pride? Even in the first movie, it only served as a place for Hakuna Matata, and as soon as Simba returned, we never see it again. Simba's Pride only deals with the Ouldander/ Pride Lander relationship, so there is no real reason for the jungle to be in the movie. Although where Zira came from all of the sudden is a very good question, and I have no doubt that there are many topics about it already.