Sorry. My brain just filters out codeshares !
If connecting things are nicely organised. All the non-Schengen flights (ie both MAN and SVO) operate from gates 30-35 which are all together, only takes a minute from one to another, so the 45-minute one should be no problem. They're good at quick baggage transfers too (if you're not a Russian speaker dealing with misrouted baggage after arrival in Russia is a nightmare).
If the 3 hour connect you can go through the passport control into the main part of the terminal (following the transit signs). There's a nice choice of shops and restaurants, and a good view out over the field, to pass the time.
The Aeroflot flight is on an Airbus, the same as Finnair.