samthegooner did a better job explaining my thought process than I did - even though we have had some last second winners, most of those games we dominated and deserved to win.
Looked like you brought up those games as they were late winners rather than games we won without really deserving them. That's generally been the case with the ones we've won last season as well.
In the games you mentioned we absolutely deserved to win last season though it wasn't looking likely. More chances, more possession, more xG, more shots and passes.
https://understat.com/match/18432
Villa 2:4 Arsenal
0.34 xG 2.86
7 Shots 20
5 Shots on target 5
33% Possession 67%
293 Passes 571
Should have been easy win according to the stats.
https://understat.com/match/18452
Arsenal 3 : 2 Bournemouth
2.46 xG 1.74
31 Shots 4
9 Shots on target 4
81% Possession 19%
740 Passes 184
Another one which should have been easy win according to the stats. They only had 4 shots all game.
For the ones from this season which should have been easy wins, here they are.
https://understat.com/match/22166
Arsenal 2:1 Brentford
1.59 xG 0.73
17 Shots 9
6 Shots on target 4
72% Possession 28%
564 Passes 226
This game vs Brentford at home should have been an easy game according to the stats.
https://understat.com/match/21934
Arsenal 3:1 United
1.91 xG 0.97
17 Shots 10
5 Shots on target 2
55% Possession 45%
532 Passes 462
This game vs United should also have been an easy win according to the stats.
Luton 3:4 Arsenal
0.53 xG 2.59
6 Shots 23
4 Shots on target 9
33% Possession 67%
296 Passes 589
This game against Luton should have been another easy win.
That said, some games from the list from this season are games we were fortunate to have gotten away without losing.
However this win from earlier in the season against Brentford was closer than the Villa and Bournemouth games from last season.
https://understat.com/match/22015
Brentford 0:1 Arsenal
1.66 xG 1.83
9 Shots 15
3 Shots on target 4
36% Possession 64%
298 Passes 508
https://understat.com/match/21965
Arsenal 1:0 City
0.39 xG 0.86
12 Shots 4
2 Shots on target 1
49% Possession 51%
500 Passes 521
We were also fortunate to get out with a win this game against City.
Chelsea 2:2 Arsenal
1.72 xG 1.06
11 Shots 13
5 Shots on target 3
43% Possession 57%
443 Passes 570
This was another we were fortunate enough to get away with even a draw tbh.
These are just looking at the late wins this season vs the ones you mentioned from last. I can't be bothered going through each win especially from earlier this season as there were definitely more games where our performances weren't as good as most if these with the last wins where we won despite not creating much.
Our gameplay has dramatically improved defensively and offensively since the Christmas period compared to previously and we have been well worth every point we've picked up since then whilst we were sometimes fortunate pre Christmas. Havertz up top and Jorge coming into the team has made a massive difference in our setup and it's the kind of setup we continue with going into next season even if the personnel change.