1)Based on Hunter class passive perk:

COMBINED MINIONS:
- Separate mod which allows to summon only 1 minion/sentry that takes all minion/sentry slots, but has a damage boost per every slot used, configured by a user.

FORMULA: X% DB/S = BSWD + (X%(BSWD)*(M/SMS-1 where X - configured number by a user (DEFAULT: 15%)
MIN: 0% (no damage bonus or, simply - 1 minion and 1 sentry challenge)
MAX: 100% (BSWD + 100%(BSWD*M/SMS-1)) = BSWD*M/SMS
Trying to summon another minion will OVERRIDE previous minion. Doesn't affect the length of a whip (WS:M/SMS = 1:1).

2)Based on how Abigail works:

All Minions Work As Abigail (AMWAA):
- Separate mod which increases existing minions's/sentry's damage for every new slot, occupied by this minion (same FORMULA from previous idea).
Allows summoning multiple minions until the limit is reached, then there are 2 solutions:

a) works like in vanilla Terraria (chaotically overrides buffs and minions, idk how it works :/)
b) blocks using summoning weapons until the buff of a minion is disabled manually/in-game debuffs.

BSWD - Base Summon Weapon Damage [value]
M/SMS - Minion/Sentry Max Slots [value]
WS - Whip segments [value]
DB - Damage Bonus; DB/S - Damage Bonus/Slot

Tried to simplify/structurise as much as possible, I hope you like Math and reading Terms and Conditions (and all stuff which is similar to that)!

I remind you that it is UNNECESSARY to make these mods, I will be fine waiting for the port (if it happens)

P.S. I really like this mod, the idea to play the same vanilla Terraria Class differently and the classes, provided by the mod. are really unique and worth to have them ported to 1.4.4.9, not to mention that it allows me to play casually in combination with other various mods.