Got some 105 5700 shifters for a steal recently, for a cross build. Was going to mate them to a 5701 105 rear mech for a nice match but they are rare as well in ss guise (short cage not single speed duhhhh!).
Tiagra 4700 mechs are common as muck, will this combo work? Some people report issues with new tiagra shifters and a 5700 mech. Is it dross the other way round too?

Thank you in advance

Dont work, 4700 is a different pull ratio to all the older 10 speed stuff

As above, 4700 is the odd one out and is (currently) the only 10 speed road group to not use the old standard Shimano pull ratio, it uses the 11sp road pull ratio. You need any ‘old’ pull ratio road mech from 7-10 speed, or any MTB mech form 7-9 speed.

If you want Tiagra then 4600 will work with your 5700 shifters, as will 5700, 6700 or any of the older models of the groupsets like 4500, 5500, 5600, 6500, 6600, 7700, 7800 etc.

I have 5700 shifters on my road bike with an Ultegra 6700 rear mech.

You could take a look at 9 speed MTB mechs. Or current generation Sora.

Or CRC currently have a short cage 4601 10 Speed Rear Mech for under £30…

As above, the 5700 won’t work with 4700, but will work with any other shimano road 10 speed or MTB 9 speed rear mechs.

I’ve got a barely used short cage 5700 if you’re interested…. mail in profile.