Puljujärvi hardly speaks English and didn't exactly master the SM-liiga season in a way you could say he is a surefire impact player waiting to be unleashed at the NHL level.
Pulju spoke elementary English in the spring (During the WJC,
link to an interview where he starts speaking English than struggles a little being able to respond so uses a translator. This was before he started taking more English lessons. In April, he gave his
first English interview to practice. Still struggling but he's showing improvement). So with further English lessons it's not an issue. 2-months of language learning is enough to make someone with limited skills conversational in English. After training camp, he'll be fine.
Not sure if speaking English really matters. There's been quite a few Russian players who haven't spoken English. The Swedes just have everyone spoiled since they are such well spoken in English.
But there's no way that Logan Brown plays in the NHL next season and a very good chance than Pulju does. That automatically puts Brown behind in the points column.
Brown's foot speed looked better at the U18 tournament and his first steps looked less awkward, so he's making improvements in his skating, but he's no where near where he needs to be in terms of skating to play in the NHL. The same cannot be said about Pulju.