Well I guess it will get changed (and might have already been changed in the alpha version), but there are (at least in v8.3h) better and more efficient ways to boost discipline to at least 50 - if you have ie. an npc with a captainskill, as you just need one guard captain with captainskill of 100+ and put all the undisciplined girls with a discipline value of below 50 on guard duty, to get a guaranteed discipline increase by 1 (allthough you should then not employ any other guards with a discipline of 50 or more, as that would decrease the discipline increase chances). If the captain skill is lower, the chance to increase the discipline value is lower.
The thing about influence is (but I guess that might be a topic of its own) that I never really care that much about influence, I care about getting enough influence (in the beginning) to be able to get to emerald island (Crystal Heights) very early and also to be able to enter the Palace District (relatively early) and then the next threshold I care about is having enough influence to purchase HULC armors (for my followers) - which btw also cost a whole lot of money - and some other items (like Revital from the Transit Dept.). Other than that the influence value only becomes interesting again, if the influence value does go into the millions (and more). And at least getting early to Crystal Heights can be done with fighting alone, ie. clearing forts, doing daily common bounty missions (that depending on flavor can give you some influence after winning the fight as you did save some persons) etc.. Meaning it is very likely that in some certain quest I will pick the extortion option (and not the other one) and it is also very likely that I will purchase from Shady Dave (if he offers the right items).
And then in my unholy opinion there are - in the long run (as there are no daily costs involved) - better ways to increase influence values (ie. getting a guaranteed daily influence gain).
But for some of them, I probably should put up a post about the current faction mechanics first (ie. donate items, that guarantee power boosts, standing increases etc.). But as a small summary Fort Sera (after quest completion) will give you (with 150 standing) 0.5 daily influence and 2 dollar per day per point of power value (which btw means that in my current game I still voluntarily miss out on over 6000 Dollar and 1500 influence from a Fort Sera with power value above 3000, as I still did not donate the 25 automatic rifles and did not donate 150000 raanic Dollar)¹ and a faction, like the Aesir Tribe, can give you (with max standing of 150) 2.5 ranic dollar and 0.5 influence per power value (per day). Granted it will take some time until investments in power value (even with donate items which guarantee a power value increase) of factions will amortize (and time to amortize are higher than ie. the normal city investments), but then you get the influence and the dollars for the rest of the game and only some conclude day (global events) can decrease the power value (ie. the events a "Powerful Blow", which reduces the power value by 50 poiunts, can only happen to a few factions like the Aesir Tribe or the Catholic Church and if I remember correctly the power value needs also to be high enough in the first place). And if you do have a standing of 100 or more (preferable 150) you will get 1/3 of the power value of that faction (unless it if Fort Sera) added to the power value of your house, in case of Fort Sera you get the power value of Fort Sera added to the power value of your house (and at least the gold income of the goldwalking of the precious daughters of the mc/pc increase with power value...). Of course at least in v8.3 you are still not able to boost the standing of many a faction above 70 (or better 71), but then some factions can be boosted above 100 (and to 150) eventhough one must not be too attached to a certain faith (if one wants to control more than one religious factions, but ie. control catholic church, the caliphate and the aesir tribes), but be willing to be an opportunist, who switches faiths (to gain control of religious factions).
ps. As far as I know you can also sign up daughters (status=9) and wives (status=10) to the stables (and give them a horse). Meaning it is not only available to convicts, slaves and servants (but to more stati).
pps. In general it is worth a consideration to give the girls/npcs the janitor job, after they have discipline 60, to give them a chance to increase the workaholic trait, as workaholics have a much easier time to reach 100 discipline than npcs (who are not workaholics) as most discipline increases are capped below 100 (eventhough via the arena it is also possible to reach 100 discipline, if I remember correctly).
¹) It would not be right to complete the Fort Sera Questline before ie. completing the currently available chapters of the Kymanto Questline ;-). And I also like the thought of the Ikaanian republic being totally unaware (and being totally ignorant) of a big military force in the Outer Marston Swamps (which might be more dangerous than all other current threats to the Ikaanian republic as they are stationed not outside of the capital but are actually festering inside near the very heart of the capital) - ie. you will currently only get global events featuring Fort Sera (like the recruting events), if the Fort Sera questline is completed.