Hi! I haven’t posted on here in quite a while but had to reply when I saw your post. I purchased this series before really understanding CM and the importance of good literature. My two cents – this series is twaddle! For the same reason you would stay away from abridged versions of the classics, stay away from this series. Be patient, wait until your children are old enough, and have them read the fuller and richer biographies of these important people and events from history.
There are a great many other choices – truly excellent choices – for independent reading for your children at this age. Look at various booklists here on the forum, or use Honey for a Child’s Heart by Gladys Hunt to guide you…. Both options will help you to steer clear of abridged versions and other inadequate summaries of history and historical figures.