I feel the basic stable concept can work.

The trick is to keep the stable size down to approx 10 or less so that it is manageable.

Once a stable runner has had a win , then another can be sort to add to the stable.

A simple method for selection of stable horses is target 10 horses that won their last start by 3+ lengths Last Start.

Bet their next 5 runs until a win then drop them.
Then add another to take its place in the stable.
If no win in next 5 runs , drop them.

Bet 2 2 3 4 5 = 16 units
Bank needed 160 units (10 horse stable x 16 units)
The reason we use this staking approach is that their prices can be shortish at times & using that other plan could prove very expensive if the wheels fall off.

__________________
Cheers.