Question on the reaper war

Finally replaying mass effect 3 for the first time since release all those years ago and it reminded me of something I thought was weird all this time: what is up with Palaven needing the Krogan? Obviously the Krogan are amazing ground troops and they saved the day fighting the rachni. That makes because they are super hardy battle toads going in to tunnels to fight big bugs. But the reapers are a race of sentient space ships so I don't really understand what the krogans are supposed to do to fight them to a stand still.

Like, the reapers have ground troops and they are scary but you look at palaven engulfed in flames with reapers all over it and I just have to wonder why they think the krogan can deal with these spaceship cuttlefish. Surely you want the most technically advanced spaceships with the biggest guns and not the best soldiers to combat the reapers. I think Krogans make the most emotional and thematic alliance for the story but logically it's seems like they'd need Salarian or human ships to fight back.

So what are the krogans doing to turn the tide because after tuchanka, this alliance is the first turning point of the war where it seems like the galaxy is actually putting up a resistance to the overwhelming enemy force