The tonnage of this frigate class and future frigate class is very close to current destroyer class.
Essentially they will take their role like say FREMM "frigate" does.... and NGD will bump up the IN destroyer tonnage into new "cruiser" capacity role there.
The Kamorta corvette class also is ~3.3k ton displacement (given ASW these days) of many existing frigate classes nowadays....the Pohjanmaa corvette for Finland will be even larger at ~4.3k ton.
i.e High payload but lower endurance that keeps it as corvette compared to Frigate which have higher endurances in force doctrine.
i.e Classes are generally defined by endurance first and tonnage second, and tonnage is what is often seen increasing these days....I believe I mentioned this a few times already in the forum
@Ripley
This upward shift in tonnage of classes is notable worldwide phenomenon (actually since ww2) in most large navies to get more potency per hull slot in shipyard and naval doctrine evolving this way too with payload, protection and armament design drivers of each generation.
@Anmdt