The most used bomb in the world is the american Mk82, with 225kg/500pounds weight. In the era of precision guided munitions you don`t need huge payload capacity. The Gripen can carry anyway antiship missiles/land attack missiles like the RBS 15, with ranges of over200- 300km, depending of variant.
Strike in Ukraine (for PSU) is lo dash - release - lo egress profile. A lot of afterburner use to deny firing opportunities to SAMs, and range to LRAAMs. That means fuel is being burned crazy.
Current base Ukrainian strike aircraft are su/mig (both with 2 useful stryke pylons). They're effectively harmless in a2a, but they're powerful aircraft, able to haul their payloads on the deck fast. Sukhoi has lots of fuel, but low altitude flight on it isn't fun.
F-16 is a separate story, we may return there later and probably in a different topic.
That's what we're replacing.
It's oversimplified, but armed, with one tank and short pit stop, with gripen C you have to refuel in the immediate proximity to the frontline (frontline cities). It's a small aircraft, which relies on not burning too much fuel to go places.
It isn't a show stopper as long as Ukrainian AA denies Russian drones immediate kill chain(just knowing aircraft landed on an air base isn't enough unless you're nuking it, you need the specific spot), but this is of course a risk(we saw it in the past). You're also obviously time constrained - drones can be intercepted, but satellites don't sleep.
If you force Gripen to burn (like Swiss tender), it goes empty very fast. Thus, pit stop.
With 1 tank, you have 4 pylons available; 2 meteor/2 bombs, or 4 bombs, or 8 SDB.
With 3 tanks(when you can actually fly to a safe field and/or loiter in CAP), it's either 2 bombs or 2 meteors.
Plus, of course, gripen is a hot scooter when compared to available bombers (f-16/mig/su). Less acceleration/energy retention when loaded, meaning you need to start earlier and be more mindful of how you maneuver.
Advantage is it's done much cheaper, and also doesn't require too much fuel physically. Low footprint, faster fuelling.
With Gripen E, situation changes drastically as it has 3/2 central stations: you now can combine 2 tanks with main useful weapon loads, giving solid strike/self-escort advantage over all available aircraft. For example, 2 bombs, 3 meteors, or 4 bombs(two fuel destroying Soviet aircraft replaced by 1 Ikea scooter, with much faster run-around and pilot comfort).
With Rafale, because of its bag configuration(and their size) you can take full strike racks(6 250/4 500/3 1000) right from UKLS, deliver them and return to safety of a well established and defended rear base. All that with full self escort, with self escort pods always in, and with automatic terrain following not interfering with radar A2A search.
Or, screw around in a combined CAP.
Overall, Gripen C is a massive boost in sortie effeciency, plus meteors. But if we're talking actual additional capability for PSU over what they already have and can, it's basically a meteor interceptor.
Gripen E is where a big boost comes from, as it performs as a modern reincarnation of a mirage 2000.
Rafale - in it's own class.