That's not a dogfight. Those two fighters banked right and then started flying straight (you never fly straight in a dogfight.) They're flying in formation. And notice how all the contrails (at multiple altitudes) are banking in the same direction. This area looks more like a launch point for stand-off munitions.
Its the lack of EW that's puzzling.
I don't see a "lack" of EW. In the opening phase of this war, Ukrainian radars/S300s were taken out, their air bases and command centers were hit, and major ground formations taken out. Then Russian ground forces breached Kiev in less than 48 hours. You don't get all of this without EW/ECM/AWACs present at +40,000 feet, in the rear.
As for comms, we have no idea what the state of Ukrainian mil-comms and crypto is. Civilian networks are a bad indicator to judge this. We don't know what Russia is jamming and what they are allowing (i.e. hacked into and monitoring.)
Hypothesis:
Ukraine stationed it's best troops in the East in preparation for an attack on the separatists.
The current Russian offensive was meant to lure those troops into racing back to Kiev so that the Eastern forces can gain control of the entire region with minimal losses.
Do we know that the best Ukrainian units were deployed in the East? Considering the geography (Kiev has no strategic depth), I'd think they would've positioned them between Kiev and the Russian/Belarusian border. And if that's true, they're already destroyed, because Russian ground forces are inside Kiev.