Peak cylinder pressure hurts or destroys engine parts. Rods and cranks and main webs. This rod and crank system is
always out of balance. To solve that problem add-ons were invented, counterweights, vibe dampers etc. Weight is a big problem in internal combustion engines. They should be light and compact and fuel efficient, but they aren't.   Weight is a big problem in internal combustion engines. They should be light and compact and fuel efficient, but they aren't.

I became aware that engines are our handle on small puffs of expanding burning gases. (Engines bleed high-pressure air down to low pressure and spin the crank and flywheel) We give the engines credit for making horsepower. The engine only contains and delivers power when fuel is ignited inside a chamber. (The fuel is the power)

So why not give the expanding gases an easy way out, but just after they deliver a large portion of that energy to the piston tops. The piston needs to move away from that mini explosion as quick as a bullet but the rod and crank prevents it from doing so.

Detonation tries to compress the rod and crank and usually finds the weakest and breaks it. Sometimes the main webs rip out of the crankcase so the crank gets out to become a killer large piece of shrapnel going very fast and all out of control.

Sir Isaac Newton's 3rd Law of Motion is ignored, so the imbalance is ignored, so the imbalance is permanently present in these mechanicals, and some designers try to hide the vibration.

Firing order seems like disorder to me.

After chaos, one large piston firing every 90 degrees, (and some of those degrees are not fruitful) I see the valve mechanicals as very wasteful and prone. to breakage or melting. I also see the use of the pistons to move the air in and out as very wasteful of the energy. The largest bearings in engines are the mains. They get all of the pressure of every cylinder firing. They can't escape detonation. Crank engines are so low on torque they all need gears to multiply torque.