AI does too many pitstops, why?

Race Setup: Group C, Spa 1993, 30 minutes Race, 4x Tyre and Fuel, one weather slot: Clear skies, 29 AI, Custom AI xml.

I ran a Porsche, fuel wise, two stops were needed. Tyres had around 20% or so degradation after each stint.

Most AI did 4 stops in this race and I don't understand why. Especially given the following. Here are two AI Porsche drivers, same car as me. The first one did 4 stops. The second one did 2.

Code:

        <race_skill>1.0</race_skill>
        <qualifying_skill>1.0</qualifying_skill>
        <aggression>0.9</aggression>
        <defending>0.8</defending>
        <stamina>0.998</stamina>
        <consistency>0.9</consistency>
        <start_reactions>0.80</start_reactions>
        <wet_skill>0.99</wet_skill>
        <tyre_management>0.95</tyre_management>
        <fuel_management>0.95</fuel_management>
        <blue_flag_conceding>0.75</blue_flag_conceding>
        <weather_tyre_changes>0.12</weather_tyre_changes>
        <avoidance_of_mistakes>0.95</avoidance_of_mistakes>
        <avoidance_of_forced_mistakes>0.99</avoidance_of_forced_mistakes>
        <vehicle_reliability>0.95</vehicle_reliability>

Code:

        <race_skill>1.0</race_skill>
        <qualifying_skill>1.0</qualifying_skill>
        <aggression>0.95</aggression>
        <defending>0.90</defending>
        <stamina>0.80</stamina>
        <consistency>0.75</consistency>
        <start_reactions>0.99</start_reactions>
        <wet_skill>1.0</wet_skill>
        <tyre_management>0.95</tyre_management>
        <fuel_management>0.95</fuel_management>
        <blue_flag_conceding>0.3</blue_flag_conceding>
        <weather_tyre_changes>0.40</weather_tyre_changes>
        <avoidance_of_mistakes>0.80</avoidance_of_mistakes>
        <avoidance_of_forced_mistakes>0.95</avoidance_of_forced_mistakes>
        <vehicle_reliability>0.847</vehicle_reliability>

If there were changing weather conditions I would have put the behaviour on weather_tyre_changes, but that was not the case. One weather slot with clear skies. Damage from some incident wasn't a factor either, clean laps all the way, also damage was set to visual only, not sure what that does to AI. What triggered the difference in behaviour between those two?

 

I gave it another try with the same settings and this time driver 1 did 3 stops, driver 2 did four.

Bit confusing so maybe a quick summary.

Driver 1: Race 1, 4 stops, Race 2, 3 stops.
Driver 2: Race 1, 2 stops, Race 2, 4 stops.

Player: Need 2 stops for fuel.