If there's no "clunk" then either the solenoid isn't getting a feed or the solenoid is faulty.
By the looks of it, the first thing to check on the TD4 is the spade connector on the starter solenoid - the connections corrode, a clean up and maybe a slight tightening of the connector with some pliers and retest.
If that doesn't fix it, try running a wire from the battery to the solenoid terminal, if it still doesn't engage, then the starter solenoid is faulty.
If it does engage, then the possibilities are...
Starter Relay - I believe the fuel pump relay can be swapped with it temporarily to see if this is faulty.
Fuse - there will be 1 or 2 fuses in the starter circuit, 1 for the keyed feed and 1 for the relay feed.
Ignition switch - this is a known part that fails on Freelander.
Bad earth - probably just from the solenoid as the other part of the relay feed goes through computers and the rest of the car looks OK.
Break in wiring.
Off the top of my head I'm not sure where the relay is, I presume its in the engine compartment fuse box, but not sure exactly where. Similarly, not sure which fuses are in the starter circuit.
If there's no input from others, you can download the Rave Workshop Manual. This has complete wiring diagrams and descriptions of everything. You can find out how to get it here...
https://www.landyzone.co.uk/land-rover/rave-disk-maintenance-manual.260227/
This is quite a regular topic - so you might find more info on searches as well.
To check if the ignition switch is working, or there's any problems in the wiring, you'll have to pick points in the circuit and test to see if current is flowing to it - using a multimeter or bulb etc.
These are things I can think of.