Well, the 11-87 has a reinforced and pinned fore end that the 1100 does not, and incorporates a gas shroud, but you are saying the 11-87s split more than the 1100s? I have owned 13 of them myself over the years, and worked on hundreds, and the only split fore end I have ever personally encountered was when the gun was dropped, so yeah maybe that is normal use.
What could have happened... did.
I do not trust Remington's dating service accuracy. If they were Match.com, you could end up with Nancy Pelosi.