WI: 'push-pull' aircraft introduced in ww2 airforces

This is a regular fruit salad. It contains not only apples to oranges orange comparison but also cherry-picking. I really don’t feel as if it’s worth going into at length, but here are some quick comments on just one of the comparisons.

I'm sorry that you feel that I'm cherry picking here.

In comparing the Me410a with the Mosquito F Mk II, the Me 410a had more horsepower and was about 18-20 hp faster. The Mosquito carried 4 cannon and 4 machine guns but couldn't carry bombs. The Me 410a had two 20mm cannon, two 7.92 mm guns firing forward, and two rearward 13.2mmg guns in turrets. The later FB MK VI Mosquito had more horsepower and depending on the sources was either the same speed as the F MK II or the same speed as the Me410.

Let's compare the two.
At rated altitude of 5.7 km (~18700 ft), the DB 603A makes 1620 PS (~1600 HP). At same altitude, Merlin 20 (and 21, 22, 23, 24, 25; link) will do 1100 HP. So the 410 has a ~50% surplus of power, yet it is only 5% faster. Granted, the speed will not increase in a liner fashion with increase of power, but this shows just how much draggier 410 was than Mosquito, despite not having the wide fuselage, wide pilot's comparment, while having a smaller wing (10% less of wing area than Mossie).
The Mossies with 2-stage engines were faster than Me 410, even the, obviously, armed night fighters, with flame dampers.
But let's also throw the Me 210 in comparison. More power at altitude than Mossies with 1-stage supercharged engines, thinner fuselage and cockpit, still not faster than the said Mossies.

In comparing, the Do335 and Me410, you’re comparing a 1944-45 single-seat experimental aircraft a 1938 two seat design that was by 1942 was debugged and combat-proven machine.
One single seat prototype Do-335, with DB 603e engines and using MW50 flew 474 mph—and without the MW boost, it did 424-426 mph, iirc. The Me410s had the 603a and no MW50 boost did around 388.

Apart from layout, there is no ground breaking things on the Do 335. It even used the same basic wing profile as the Me 214/410 - the NACA 23018. Pilot and gunner were seated one behind another in the 410, so crew is a moot point here.
With DB 603A, Do 335 was good for ~720 km/h, or ~447 mph. A 60 mph surplus vs. Me 410; link
The two-seater humpback night fighter ( with 'antlers' and flame dampers) was still good for ~690 km/h, indeed 428 mph.

So this prototype Do335 is around 36-38 mph faster than Me410. It would appear that most prototype Do335s carried no armament whatsoever, let alone the motor-cannon of which you’re so fond. I believe V-13 and V-14 carried weapons, but I don't know their speed. A couple of two seater Do335s were built, and carried antennas but weren't fitted with radar, or weapons I know of, and I don't know their speed or if they even flew. The Do335 had no rearward firing weapons and no capability of carrying rearward firing weapons. The Me-410 did carry these in a clunky system—but that’s what LW had required.

The barbettes were no more clunky than the elevated second cockpit on the NF Do 335 version, or 'double' windscreen on the Mossie, stil such 335 id faster by 30 mph than as clean as possible Me 410.
I don't know where from you've found out that I'm supposedly fond for a prop gun, though. A good feature in some cases, but not a must.

I do know that the Me-410 had excellent visibility from the cockpit and the Do-335 did not.
A more reasonable comparison would be between a single seat, stripped version of the Me410 and a Do335 that was designed in 1938. Of course, this can't be done.

Stripped 410 would've gained some rate of climb, but speed - maybe 5-10 mph?

I could go on, but I feel that there isn’t really a point in doing so.
I’m not saying that Bf 110, Me210/410 were great.
I’m just saying is the comparisons you make aren’t fair comparisons and while I love push-pull aircraft, I really don’t think that the trade-off in the design make it worthwhile layout.

I've tried to compare aircrfat that were using same engines, and about same wing profile and size. That in such a comparison a classic comes out as second best does have nothing with me.
 
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