Complex sentence: A total size of družina is estimated by Ruttkay to 3000-5000 warriors, a maximal size of the army can be estimated to 20.000-30.000 men.
Split into simpler sentences: A total size of družina is estimated by Ruttkay to 3000-5000 warriors. A maximal size of the army can be estimated to 20.000-30.000 men.