Using redstone wire to activate multiple command blocks is outdated since 1.9 because you could use command chains instead and since 1.12, you could even use functions. To keep the concept generally applicable and overviewable, it would be better to list the commands and just give the option of using command blocks while still leaving space for better alternatives. Tick-Based randomizers have been used for a long time, but they don't work well for many cases and have obvious flaws. Commonly used methods in modern times would be scaling down UUIDs, using loot tables, using predicates or using pseudo-random algorithms like LCG.
There are libraries or native implementations for each of these methods. The libraries are, beyond others, featured by the RNG module of the Minecraft Phi data pack. Kappascopezz (talk) 00:23, 5 March 2020 (UTC)