How many T9/T10 troops need to be exchanged for ~10k points in Conquest of Lords?

I'm trying to plan for my next Conquest of Lords event.

We get around 2,000 occupation points, so I only need about 10,000 points from troop exchanges.

In the current COL:

- I had 10,750 points.

- I missed about 300 occupation points by 20 min

- I needed around 1,250 more points to reach my goal.

- I estimated that trading about 75k T9 troops would be enough.

- After the exchange, I received 400 points from kills and 1,600 points from dead units, finishing with 12,750 points.

For players who regularly plan around troop exchanges:

- Roughly how many T9 troops need to be exchanged for 10,000 points?

- How many T10 troops would it take instead?

- Is there a reliable rule of thumb or formula you use to estimate COL points before the event?

I'd appreciate any calculations or examples from your own experience. Thanks!