How close are you to renewal on the XJ? It is possible that the scheme you are on is preforming well.
Insurance, at underwriter level, is generally based on 3 criteria; Risk, Burn rate and maturity.
Risk - Age, postcode, experience security etc.
Burn rate - The amount of money paid out against money paid in on that scheme.
Maturity - How long the scheme has to run before the underwriter renegotiates it.
What they are looking for is for the scheme to have a low burn rate (low pay out rate) over a maturity that is coming to an end. This increases their chances of making money on the scheme.
I used to work for a company that sold insurance products. This included Triumph.