Comparing the Flight 93 Crash with the Recent Nigerian 737 Crash

Links for the Nigerian crash here, here and here.

This story is very recent and has the most pictures.

Detail of the Nigerian crash:

Dismembered and burned body parts, fuselage fragments and engine parts were strewn over an area the size of a football field.

A wig, human intestines, clothes, foam seats and a hand were seen wedged in the sodden earth. A check for 948,000 naira ($7200) from the evangelical Deeper Life church was one of a number of personal papers found in the smoldering wreckage.

Similarities:
1) a medium size Boeing jet (757 for UA93, 737 for Nigeria jet) crashes at high speed in soft ground (filled in mine for UA93, swamp for Nigeria jet).
2) the plane disintegrates upon crashing, leaving a large crater (some pictures n the links).
3) passengers are all killed, bodies are mostly torn apart.
4) the crash was very violent, in both cases "small bits of fuselage, human flesh and clothing were strewn in nearby trees."
5) the debris fields are similar sizes

Differences:
1) the Nigerian crash was on fire for over a day, unlike UA93
2) the Nigerian jet does NOT disappear into the ground, unlike UA93 supposedly did
3) most importantly, large easily-recognizable body parts and large plane pieces were strewn around the crash site and were easily found, unlike UA93 where no plane parts were near the crater and human remains were in very small pieces-- mostly pieces of skin.

So-- why so many similarities yet so many major differences?

Why does the flight 93 crash defy logic, unless it is faked?