it actually isnt that hard itself
but YOU play the major role in it
small projects are mostly done by one person
but some mod devs actually let their mod reusable and are even ok with letting you check inside to see what the fuck is going on there
some devs even joke about it putting messages in the lua files =)
unfortunately srb2 is so complicated that its near impossible to simplify character making exept if we change the engine
(thats kinda how modding is easier in 2.2 now)