Yes, but DDG is sat on 17th/21st in terms on save% who played more than 10 premier league games in that position when we are the 4th "less shot on target against" team, including Ryan played 11 games at Brighton. I don't think this is a standard of a team who want to compete a tittle.
When the team want to challenge a tittle, it should not have a visible weaken point in the whole squad.
(P.S. I do not have a clean cut chance against stats on hands, so i do not know whether it is depended on defensive tactic.)
The awful is, DDG at 17/18 Jose Team is the one and only GK that have 80%+ saving (140 numbers of shot on target against, 3.78 per games) in full length of the whole season since 2010.
Then, I think when we have a mid-table rank goal keeper, we can walk far than now.
For your reference,
Rank | Name | Team | Match | Goal Against | Goal Against per 90mins | Shot on Target Against | Save | Save% |
1 | Martinez | Aston Villa | 27 | 28 | 1.04 | 122 | 94 | 78.7% |
2 | Ederson | Man City | 29 | 20 | 0.69 | 60 | 47 | 78.3% |
3 | Nick Pope | Burnley | 28 | 32 | 1.14 | 130 | 101 | 77.7% |
4 | Areola | Fulham | 28 | 33 | 1.18 | 119 | 92 | 77.3% |
5 | Lloris | Tottenham | 28 | 30 | 1.07 | 100 | 79 | 77.0% |
6 | Mendy | Chelsea | 24 | 16 | 0.67 | 57 | 43 | 75.4% |
7 | Meslier | Leeds | 27 | 45 | 1.67 | 143 | 106 | 73.4% |
8 | Pickford | Everton | 23 | 29 | 1.29 | 97 | 69 | 72.2% |
9 | Alisson | Liverpool | 24 | 26 | 1.08 | 78 | 55 | 71.8% |
10 | Sanches | Brighton | 17 | 17 | 1.00 | 53 | 39 | 71.7% |
11 | Schmeichel | Leicester | 29 | 32 | 1.10 | 105 | 73 | 71.4% |
12 | Fabianski | West Ham | 26 | 30 | 1.15 | 96 | 68 | 70.8% |
13 | Leno | Arsenal | 27 | 28 | 1.05 | 91 | 67 | 70.3% |
14 | Ramsdale | Sheffield | 29 | 55 | 1.96 | 162 | 113 | 69.1% |
15 | Johnstone | West Brom | 28 | 50 | 1.72 | 152 | 105 | 69.1% |
16 | Patricio | Wolves | 29 | 38 | 1.31 | 103 | 73 | 68.9% |
17 | DDG | Man United | 24 | 29 | 1.23 | 77 | 53 | 67.5% |
18 | Darlow | Newcastle | 25 | 43 | 1.72 | 120 | 81 | 66.7% |
19 | Guaita | Crystal Palace | 29 | 47 | 1.62 | 130 | 84 | 66.2% |
20 | McCarthy | Southampton | 25 | 48 | 1.92 | 113 | 70 | 61.9% |
21 | Ryan | Brighton | 11 | 19 | 1.73 | 30 | 16 | 50% |
Source
https://fbref.com/en/comps/9/Premier-League-Stats#all_stats_squads_keeper