More jet engines!

I have a list of jet engines that I think the Devs should add (sorry for my bad English)
-pulse jet
Pulse jet engine is the weakest jet engine, it creates a buzzing sound whenever in starts up. The fuel efficiency is somewhere between a turbojet and an afterburning turbofan

-ramjet
Ramjet is the most powerful engine jet engine, it can't start up without a bit of momentum, it has to be placed outside the fuselage, it cannot start up if placed inside the fuselage even if you have inlets. Its the most inefficient jet engine

-non afterburning low bypass turbofan
I think we need a fuel efficient low bypass turbofan engine, maybe you wanna build a fighter jet without the afterburning jet engine. Its fuel efficiency is somewhere between a low bypass afterburning turbofan engine and a high bypass turbofan engine