Are Caddy TDIs with 105 hp and 75 hp identical (except for the engine control unit)?

The current Caddy models include engines with a displacement of 1.9 liters, among other options.
PD-TDIs with 105 hp and 75 hp were installed (since 2006).

I would have assumed that at least Turbo...
and possibly also pistons, connecting rods, etc.
differentiate.

Elsewhere, it is claimed that the engines are capable of speeds up to...
The control units are truly identical.

Can someone help me with that?

Best regards, Klaus.