Squids eat green power bugs
Hideauze eats fusions bombs (see ep1)

The Squid attacks Ledo because Chambers is basically a super bug producing shitloads of energy.
Energy will be the link and basically the threat is basically scaled from earth to space in order to match the strenght difference.

Now, I just want to enjoy the series and not care about why, how, plot points or bad animations. Sometime you gotta just enjoy it, consume and be consume by the entertainment.