Those people that did the calculations and said that 100 would be hard to climb probably did not factor in the bonus medallions.
For those who aren't that good at warring, they will most likely be unable to obtain the bonus medallions which makes the trek to 100 medallions harder. This makes sense cause getting 100 medallions shouldn't be a easy feat and everybody shouldn't be getting there.
The only problem I see is for the people who are good at warring and have a chance to receive the bonus medallions, but are unable to because they sacrifice personal gains for the team win. Take me for example, I'm not the best warrior out there, but I can handle myself, get KOs and stuff. I also track, and I'm usually tracking when I'm warring. My first match I was able to get some bonus medallions.(my team wasn't that good, was able to get top plunder and KOs while tracking, we lost though) but I was really lucky to get those bonus medallions. I'm usually very busy with tracking, and so I rarely do great.
I'm ranting I know, but I wish there was some way to reward the people that sacrifice personal gain for team glory.