So what if there's less swinging? They'll never learn HOW to
control the swinging by engaging the stabilizers if all they do is
smith press. There's very limited carryover to the real thing. If
you wanna get it right, get it right from the start, even if it
means using just a 10kg barbell.
Besides, the smith machine(and any other non-cable machine) damages
your joints over time. This horse has been beaten to death yet now
and then people still come in and say the smith is safer...