I don't know anything about the sensah shifters but they look like shimano clones that work with tiagra 4700. 4700 is actually a pretty specific groupset since it is 10 speed but it uses 11 speed road pull ratios so you can use 11 speed (5800.6800,r5000,r8000, ultegra rx, GRX 400/600/800) RDs but not older 9/10 speed RDs. I'm also not sure which front derailleurs work best with that pull ratio either. That groupset they are selling has sensah shifters and a 105 R8000 long cage RD which should work well together.
If I was looking to build a mullet setup i would pick up 5700/6700 10 speed road shifters and a 9 speed deore, or a complete 4700 groupset