The cause of megafires is usually inappropriate fire prevention, which in fire-prone ecosystems means that fuels accumulate, meaning that the fires will be bigger. The more money thrown at preventing fires, the higher the fuel load. Eventually, the fuel load exceeds the capacity of the fire-fighters and a disaster happens. The cause of the disaster is the fire fighters and the logic that fires need to be suppressed. The easiest way to prevent megafires is to burn more often. It is a no-brainer.
In Med ecosystems, the fire season is the hot dry season (versus hot wet: which suppresses fire, or cold wet; in our non-Med southern African systems the fire season is the cold dry season: basically wet prevents fire spread and hinders ignition).
Hot dry summers means that biology stops working: just like cold slows down metabolism, lack of water stops metabolism, so both plant growth and microbial/fungal decay cease as well. So fuel accumulates rather than decomposes, which is why Med ecosystems have the most spectacular fires (after fools try to suppress it, creating the megafire problem, etc.)
The situation in your photograph illustrates why aliens, with their lack of biocontrols, and consequent rampant growth rates, create huge amounts of biomass at 2-5 times the rate of indigenous plants, and thus are a MAJOR fire hazzard. A summer fire ripping through here will be spectacular, but the stacks will create such intense fires as to destroy the soil seed banks, as well as destroy the soil structure (not just the organics, but alter the soil minerals, and sublimate some elements), and greatly increase the soil erodibility. Keeping fire out of these stacks is a nightmare, so a wet season stack burn is recommended, after the soil is wet enough for the surface water to protect the soil and seed banks beneath: basically instead of baking at 600-1200*C, the soil just boils (also the wood is wetter, so the fire temperatures are much lower).
An option not explored would be to irrigate the stacks in summer, thus allowing decomposition. However, huge amounts of water will be required and Cape Town is short of water, and the end of summer often sees concerns about “day zero” as demand outstrips supply. Salt water will not work, and would destroy any rehabilitation, or passive regeneration from seed banks (assuming anything else can compete with the Wattle seed banks which are often hundreds of thousand seeds per m2).
By far the best solution is not to allow these alien stands in the first place. They are illegal - and in this case the culprit is an absent, overseas landlord, who probably brought the area as an investment for development, so allowing the aliens to destroy the Fynbos allows one to get around the EIA and development restrictions, by simply paying the minimal fines for having the aliens.