Easyjet's policy explicitly allows you to spread the weight across the bags. See http://www.easyjet.com/planning/baggage

"If you are travelling in a group of two or more on the same booking and have booked bags, you may spread the weight of your luggage across the bags. For example, two passengers with a bag each may carry 20kg of luggage each, but if you wish to put 18kg in one bag and 22kg in the other, then that’s okay with us. You’ve just got to remember that you cannot exceed the 40kg total weight allowance without paying additional charges. A few really important things to remember:

•We support health and safety guidance for checked luggage and recommend that you keep the weight of each individual bag below 23kg wherever possible.
•Legally we must apply a maximum limit of 32kg so any individual bag weighing more than 32kg cannot be accepted!"