Scotland chased down a modest target of 123 at the expense of just two wickets to register three wins in as many matches.
Chasing Bangladesh's total of 181/7, PNG was bowled out for 97 runs.
"They're a terrific side, they've got all bases covered and (have) some serious match-winners," Smith said.
Andrew Balbirnie's Ireland will now have to beat Namibia to make the Super 12s.
Captain Rohit Sharma scored 60 and his opening partner KL Rahul made 39 as India chased down Australia's total of 152/5 comfortably.
The Dutch side had high hopes from experienced Roelof van der Merwe (6) but he also fell cheaply off pacer David Wiese.
Slater's manager Sean Anderson declined to comment on the reports.
Chasing Bangladesh's total of 153, Oman could only make 127/9 with Mustafizur Rahman bagging 4/36.
Scotland grabbed the top position in Group B with two wins having shocked Bangladesh in their opening game.
Cricketer-turned-politician Gautam Gambhir too supported Pathan's observation.