Simple vacuum tube tester design
The short answer to your question is "no". A voltage divider has too much output impedance to feed the dozens of milliamp tested vacuum tubes will need to be tested accurately. The current drawn by the tube will change its pin voltage hence change the measure.

Even a basic tube tester is not a simple project but an interesting one, especially regarding the power supply. IMHO you would better use a FET regulated power supply (in French unfortunately but google will translate that for you). Maybe the negative power supply used to set the grid 1 voltage will not deliver current and can be adjusted using a voltage divider.