Although as I stated earlier I am peeved with the size range in the Mid-eighteenth century figures, sometimes things do go well.
With the Early Renaissance/Italian Wars I use figures from Airfix Sheriff of Nottingham and Robin Hood for Henry VIII, Conquistadors from Revell and Ceasar Miniatures, Landsknechts and Heavy Cavalry from DDS, Spanish Army from LW and now the very extensive and still growing range from Red Box and all of these figures with more than forty years difference and a wide range of companies are all in scale with each other. This must prove that it is possible. The great thing about this period and the extensive range of companies is the incredible variety. I even have a couple of metal cannons which are sold as key rings from English Heritage sites with crews from Pikemen in the previously mentioned sets.