It seems that being the guy in front or side ranks of a column or line were significantly more dangerous than being the one in the middle so its probably something a soldier normaly would try to avoid. So how did a soldier ended up in such position? Was there a set place in formation for each soldier / subunit? Was he just slow/unlucky while unit where getting into formation? Was he placed there as punishment. Are there any historical records mentioning soldiers trying to weasel out from it?
The line company had set places for men determined by their rank.
A British company had 3 officers(1 Captain, 2 Lieutenants + Ensigns), 5+ NCOs ( 2-3 sergeants & 3+ corporals), and anywhere from 50-100+ privates.
The Captain of a company would stand on the company's right or left flank depending on its position in the battalion. A "covering" sergeant would be directly behind him. They would be in line with the front and rear ranks of the company. The other officers and/or sergeants would stand directly behind the 2nd rank, near the flanks and center.
In the company itself, corporals would be on the flanks with the privates making up the bulk. As for the placement of the privates, the company was divided into two sub-divisions which were in-turn divided into two sections. 100 man company->two 50 man sub-division->four 25 man section. So there were always set places for each private in the company.
A British battalion was made up of 10 companies. The flank companies(Grenadier on the right & Light on the left) were the elite of the battalion. It wasn't punishment but a privilege to be a flanker. The rest of the companies were numbered 1-8 so when a full battalion was formed in line it went G 1 2 3 4 5 6 7 8 L(though the Light Company often fought detached as skirmishers). So, a private's placement in the battalion was based on his assigned company.
Now, on the idea of soldiers trying to weasel out of a battle. First, there was a distinct reason that there were officers and sergeants behind the company. They kept an eye on the men and made sure they kept moving forward. A officer with saber drawn or sergeant with pike could be very persuasive. Next, the most common way for soldiers to get out of a battle was to help their wounded comrades AKA Skulkers. There are numerous reports that one wounded man would often be helped to the rear by 5 or 6 men. Napoleon issue orders that no one was allowed to leave ranks to tend to wounded during battle.
There is actually a great picture that shows where a French soldier would be in the pre-1808 Napoleonic Era. Here's a similar picture but for Column formation. It's a very similar setup I hope you recognize from what /u/pllew1 mentioned: Sergeants on the rear with the lieutenant and corporals on the corners to keep everyone together while the Captain leads from the front.
