You're installing fpc from the tar archive and attempting to install lazarus from the deb package. The two don't know each other. deb only knows dependencies against other debs. tar archive knows nothing about dependencies.
Even then the problem exists:
- installing fpc from deb (bin + src)
- trying to install Lazarus (from deb) gives an error if an older fpc version was there too (installed by default on a clean Ubuntu desktop).
The package mgr will not see the newer fpc. It only works probably when
no previous fpc was there.