Ls Land Issue 9 Cards Castle Hit
The above mana base cannot yet support History of Benalia or Thrashing Brontodon. If you would like to consistently cast 3 mana double-colored cards on turn 3, then you need 18 sources of that color. To go from 16 to 18, you could replace some basic lands with Selesnya Guildgate or Flower // Flourish, increase the land count, and/or rely on non-land sources like Llanowar Elves or Adventurous Impulse. You could, of course, stubbornly stick to 16 and accept a lower level of consistency, but I would consider that greedy.
ls land issue 9 cards castle hit
Steel Leaf Champion, which requires 23 green sources, does not yet fit in the above mana base. You can get there by increasing the land count, by relying on non-land sources like Llanowar Elves or Adventurous Impulse, by replacing a few Plains with Unclaimed Territory, Selesnya Guildgate, or Forest, or by accepting a lower level of consistency. But in a deck with Steel Leaf Champion, I would restrict myself to splashing only single-colored cards for turn 3 or later. For example, splashing Knight of Autumn off of 11 sources is doable in a properly constructed Steel Leaf Champion deck, but you should take care before stretching the mana base further.