If you are making comparisons between models from different manufacturers and sensibly analysing whole life costs. Seek independent advice from someone who is unbiased; if you are being advised by a manufacturer or dealer then the balance will probably swing in their favour.
It could be the case the vehicle you have selected is the most cost effective over the lease period, “make sure the correct fleet discounts are being applied across each model you have selected”. If you’re receiving a 25% fleet discount on Vauxhall or a 30% on Ford then this needs to be considered in the "whole-life-cost" calculations.
Some manufactures are using this to their advantage as their fleet discounts are lower; overall their product seems to be great value until the correct discounts are applied on the other models being selected.
Other considerations need to be taken into account when analysing whole life costs to make an informed decision.