Just to clarify, when you say top of the market, are you including FA? Especially this article, it feels very much that we should not expect the Cubs to be in the upper tier in that aspect: no Burnes, and I'm pretty confident no Fried. I suspect, especially with the other article (and this one) where they're talking about their scouting and analytics that if they go FA for a pitcher that the pitcher is going to be someone they can work with and build up. Unless that top of the market is Sasaki, but he's only top of the market talent wise. In terms of cost, he's basically free.
I do think they'll go after almost every and all of the best SP's who are available via trade. "Aggressively pursuit" was used by the Athletic boys, and while they rarely let their guard down in terms of very specifics, their veil can be more transparent, IMO, on wording and phrasing. Usually when they say things, it's good stuff to tuck away.
So while I think they'll pass on being aggressive on Fried or Burnes, I could see Crotchet or a Mariners SP, or even a SP we don't super expect on the market to be guys they target.