A three-squadron cruiser plan for 1880s Brazil

What mix of armoured, protected, and unprotected cruisers would suit Brazil in the 1880s?

The recommended force has four armoured cruisers, eight protected cruisers, and twelve each of torpedo gunboats and ordinary gunboats, organized to support three cruiser squadrons.

The proposal distinguishes small composite gunboats from cruisers large enough to justify a protected deck. Coppered wooden bottoms and simple construction would make low-cost gunboats easier to maintain at undeveloped naval stations, while a cruiser above roughly 2,000 tons should receive deck protection. The recommended Brazilian force keeps four armoured and eight protected cruisers but expands both smaller gunboat forces to twelve. Divisibility by three supports three cruiser squadrons and lets each operate with four torpedo gunboats and four ordinary gunboats. The same arithmetic permits roughly four small ships of each type to patrol at a given time while others train, refit, or remain unavailable. These inexpensive craft also give a smaller power visible numbers for deterrence, even though they would not survive a direct clash with major combatants.