well, if that what you want, don't think it's wrong.
any ficitonal league -- sim 20, preferably ~25-30years, by starting that many years "early." erase entire league history at intended starting date. you can delete retired players and purge db if you want to be very thurough. then, make a backup -- if still ~500mb or larger, delete contents of that backup directory, and click backup again, just the normal "backup" as before-- only the bare minimum + incremental stuff will be copied over -- you will need to reload logos and such if oyu do this last part, but it will lop off hundreds of MB. after that, it's just like a new league and non seed players -- all fictionally produced and alotted by the simulation. (BIG difference in distribution of talent... things will be "normal" after this point. easier to manipulate / test / understand). make a template now if oyu want to avoid that 30-year process in future, but you start with those players each time.
i change what i don't like about RL baseball... one example - tv nonsense affecting schedule and other things. i also don't want bad ideas that are 100 years old sticking around
i've yet to do it, but at some point i'll start a league in 1871 with fictional players and let it run to present day -- auto-importing historical LTM/LT so that it somehwat follows the real world era changes and such, or make my own. i do like starting fresh, but a 100+ year history is really coold, too.
anyway, do as you want... i re-do the entire financial environment, i make parks neutral, i tailor their capacity to market size etc etc... balanced schedules within each 10-team division to eliminate as much off-field randomness as possible relative to making the playoffs. in the past i did 40T so as to have 2 subleagues and an ASG, but lately i just chop the ASG out and do 30T 1 sub-league.
i re-use RL team names for the most part, but have have replaced 2 teams out of 30 in my most recent leagues i've created. indianapolis hoosiers and las vegas knights replaced AZ and MIL. bit of a pain re-working the MiL system, but i can make a template during game creation to avoid that mess if i need to restart, in addition to backups.
But, i want an MLB-like feel. my LTM/LT may not always reflect a steroid era, but they do reflect some idealized version of the mlb.
if you do anything like re-structuring or re-using things etc.. make use of a spreadsheet to keep track of stuff. the pic just shows league structure,market sizes with averages for division and league-wide.
the payroll column requires a bit of translation - think thats 30m less than average revenue for that market size or thereabouts. used for inaugural draft payrolls etc... the LT sheet (*oops can't see it, but it's the 2nd worksheet) maintains a set of default mil totals and also the ones i use for the majors. mostly formulas, so that when i change hits or doubles the avg/obp/slugging/babip stuff all changes in tune. at this point i don't often change my league totals.
everything is actually calculated from market size, but you can just type it in too... if you use formulas as much as possible,it's more automated and re-useable, though.
guess who controls a 10mkt size in the east?
the game will likely boost somethign in the east in short order. it stays pretty averaged out over time. a 5-6 market size average is a good goal if you try to dabble inthat. revenues wil be different based on settings - e.g. i don't let owner get invovled, and nat'l media is 50M not 40M. rest default with 250m cap / 7 year max terms. heavy 100% tax over 150% average payroll.
even though it looks like certain teams should dominate, the 3+ market sizes do just fine. 250m cap helps. they can get to 185m at least. shows how key an AI GM strategy is. i ran WAS as an 8, and they were the most dominant in teh setup below (swapped 8&9 with indinapolis).
it contains all the mil teams, but i cropped that off dince it's just redundant. i definitely recommend more than the default R-sa-a-aa-aaa fictional mil system. 2-3R, even 2 A's is a good idea. if you do 2 a's have at least 3rookie and a short a... or 4 rookies and optional short a. probably don't want multiple AA or AAA