Each universe is just one of many possibilities inside the Multiverse and in each different universe; different variables can happen with people being born at different times. Suppose in a family of 11 the eldest and middle children of the family had their ages and placement switched around?
This is the sort of universe that we find ourselves in inside the Loud House where the first born child was a boy who grew up helping with his 10 younger sisters as were born. Said eldest child was too big to stay in what used to be a closet so he had his own bedroom which actually acted as the largest since it was the basement of the house.
The great space was good for him and plenty of room to hang up his posters and put up his figures mostly of Ace Savvy but it meant that for him to be able to make it to the bathroom before his sisters in the morning, he had to get up earlier than h did but he had plenty of experience with planning.
In said basement Lincoln was reading out his schedule plan to his best friend Bobby Santiago, "So on Monday once I help Luan with her act, help Lucy with her poems, Lola with her pageants and Lana with fixing her animals then we will be able to watch the next episode of ARRGH together." Lincoln told him and he looked excited and scared at the same time.
"I just hope that they don't find another skeleton this time..." Bobby replied and Lincoln laughed as Bobby had screamed so loud somehow his mother had heard it all the way from their house despite the fact that they were watching it at the Loud House. "But we are still good on watching the monster truck rally together?" Bobby asked Lincoln who then squealed with excitement.
His excitement died down as they both heard shouting and arguing up high and Bobby followed Lincoln up as he sighed while going all the way to the top floor of the house. "I swear Bobby, it seems that this happens when Mum and Dad aren't here and I am in charge..." Lincoln told him and reached it to find Leni and Lori having a tug of war with one of Leni's old dresses with Luan, Luna and Lynn joining in and taking sides.
"Lincoln, like can you please tell Lori not to go my old clothes since she might ruin them. Plus you remember how much this particular dress means to me, the first one you helped me pick up?" Leni asked as Lori looked his way.
"Lincoln, can you please tell Leni that she literally doesn't fit in it anymore and it might as well go to me?" Lori retorted as Lincoln took a deep breath and closed his eyes for a second.
"I swear that my life would be much easier if I wasn't the oldest..." Lincoln thought in his head as he faced his siblings. "Listen, I think you girls should be mature enough to act like adults about this. So why don't you sort it out yourselves however it takes inside here in the house? Until you do I don't think that I will be needing these." Lincoln said bringing out his car keys as empathise of the implied threat causing them all to stop and blink for a second.
Leveraging the threat of him not driving them anywhere where they wanted to go was a go to tactic to get them to behave.
Lori then let go of the dress and told Leni "sorry Leni, it's still your's and I should have asked if I could try it."
"Sorry myself Lori since you're right about it like not fitting me and you can borrow it when you like." Lori said and Lincoln showed that he was satisfied with Luna, Luan and Lynn giving their thumbs up at the bullet being dropped. Among the Loud sisters they had a certain Sister Fight Protocol:
It basically involved trying to make sure that Lincoln didn't notice their fights (basically failing miserably most of the time) since his methods at putting an end to them were quite underhanded.
They started going back to their rooms and Lincoln and Bobby were going back downstairs with Lori trying to sneakily follow them but Lincoln reminded her "back to your room Lori, remember you're still grounded from what happened with Clyde." Lori's classmate and their neighbour Clyde had a big crush on her which was ridiculously one-sided and she had gotten Ronnie-Anne who was Bobby's sister to start picking on Clyde threatening him to stop. It basically got them both grounded and having to give big apologies to Clyde and his dads.
"Come on Lincoln, I think I have learned my lesson and Mum and Dad aren't here so can you do your little sister a favour and let this slide?" Lori asked putting on the puppy dog eyes but Lincoln just smirked.
"Sorry Lori but no, besides thanks to overuse by our sisters here I have become immune." Lincoln told her and Lori then began looking angrily at the directions of Luna, Luan and Lynn who were peaking through their doors.
"Don't be angry at me! I was still practicing the look when Luan overused it!" Lynn protested as Lincoln laughed as he went downstairs with Lincoln.
"Ronnie Anne tried to sneak from the house to follow, so we are both basically being crushed on by the other's younger sisters." Bobby told him and Lincoln sighed shaking his head.
"I still don't know what you are talking about Bobby as Ronnie Anne does nothing but insult me, calling me 'Lame-O' and throw stuff at me. Despite what cartoons say that's not what girls do when they like someone!" Lincoln told him and Bobby rolled his eye as they went down back to the basement.
"Speaking of girls interested in you... Are you set for you know what?" Bobby asked and Lincoln nodded checking around to make sure that no girls were around. Lincoln was planning to go to a study date the next day and wanted to make sure his sisters didn't find out and would interfere.
The sisters looked up to Lincoln to the point where they thought that it was their duty to help out their brother when they found out he was on anything close to resembling a date or there was a girl his age who he was interested in or was interested in him. Lincoln appreciated the thought but the problem was that his opinion over whether he had actually wanted them to intervene was a low priority for them and it could get disastrous.
Especially since in these schemes Lori was the ringleader and had in her head a pretty high standard for what a girl had to be to be worthy of her brother.
In the aftermath well... Rachel was now willing to be near him again after some time. They then discussed the plans for the next day not noticing Lucy who went down to ask Lincoln about what he thought of her new poem. She instead went back up to tell the other girls what she had just heard.
Just a funny little idea I had in my head and with credit please feel free to pick this up and expand on it.