For what it's worth, FIRS is actually pretty much inspired by RT2 and RT3 - that's why I knew the link to the RT3 cargo-chain image
Maybe we can make (eventually, some day) RT2 and RT3 economies for FIRS. Well, as close as possible.
Looking at http://hawkdawg.com/img/rrt/rt3/1024_Industry_Chart.jpg
, only the military and nuclear chain need to be dropped and then the big lot of the remainder is already planned for FIRS.
how about some groundwork first? i recal RT3 had few features that are missing in OTTD that made its economy playable instead of micro madness, its not who got more cargo-chain's or shall i say the biggest ~locomotive but about how it adds to gameplay.
look at the multiplayer trends, most even if they use industry's grf concentrate on small number of products and big nice networks.
so the way i see it,industry sets future is expanding playability adding interesting scenarios and not trying to max that top industry limit.
but hey that only my opinion, others may feel differently ...