That's not the only similarity. The armies are basically the same across all the Starter Sets - including Age of Sigmar's Starter Set and Spire of Dawn. The good guys have a major leader (Lord-Celestant, Space Marine Captain, High Warden), a banner bearing second in command (Lord Relictor, Space Marine Ancient, Archmage), a small team of fast attackers (Prosecutors, Inceptors, Reavers), some elite infantry (Retributors, Hellblasters, Swordmasters) and ten of their standard infantry (Liberators, Intercessors, Spireguard).
The bad guys have a main leader too (Mighty Lord of Khorne, Lord of Contagion, Skaven Warlord), a buffing second in command (Bloodsecrator, Noxious Blightbringer, Warlock Engineer), a hero who encourages the standard troops (Bloodstoker, Malignant Plaguecaster, Packmaster), a monster (Khorgarath, Foetid Bloat-drone, Rat Ogres), some elite troops (Blood Warriors, Plague Marines, Skaven Weapon Teams) and a horde of basic infantry (Bloodreavers, Pox Walkers, Clanrats).
You can see the equivalents as well in the Dark Vengeance Starter Set as well. It's a set formula they use for their Starter Sets, and it doesn't seem likely to change, as they seem to have the formula nailed (at least according to their expert opinions it seems). It does allow for two separate play styles and means a balanced battle. But it's kind of funny how all the Starter Sets are the same set just reskinned.