Just throwing some numbers around ... this is interesting ...
Campaneris started his career a few years earlier than Concepcion, and those few years were some of the lowest run scoring years since the Dead Ball Era. The best way to compare them may to be break a few different metrics down individually side-by-side ...
Code:
Career
Player Career WS Pk WS WS/162 RC/27 LgRC/27 Ratio WARP Pk WARP WARP/162 BRAA OPS+
Campaneris 280 120 19.48 3.84 4.20 0.91 89.5 41.3 6.23 10 89
Concepcion 269 117 17.52 3.89 4.48 0.87 100.4 45.9 6.54 -29 88
Campaneris had a career park factor of 97
Concepcion had a career park factor of 101
Campaneris Offensive/Defensive Win Shares Ratio: 64%/36%
Concepcion Offensive/Defensive Win Shares Ratio: 54%/46%
Win Shares ranked Campaneris as a B defensively
Win Shares ranked Concepcion as an A+ defensively
Win Shares, WARP, and OPS+ already have park factors applied whereas RC/27 and the ratio to the League's RC/27 do not have park factors applied, which is why I listed their career park factors separately. Concepcion played in a tad more favorable hitting environment.
The advanced metrics pretty much agree that Campaneris was a slightly better offensive player than Concepcion, and by slightly I mean just barely, if even that. Campaneris has a slight edge in runs created (also RCAA and RCAP, which I did not list), batting runs above average, and OPS+. On the other hand, both Win Shares and BP's metrics show Concepcion as being quite easily the superior defensive player.
There's likely two main differences with Campaneris and Concepcion with the two total player ranking systems in win shares and WARP, namely 1) how much weight is credited to defense relative to offensive value, and 2) how much superior each system views Concepcion over Campaneris defensively.
Per 1,450 innings (roughly 162 games of innings), it looks like Concepcion's defensive win shares advantage is somewhere around 1.5 win shares. That's the equivalent of about a five run advantage defensively for Concepcion over Campaneris per full season of innings. BP's fielding runs above average gives Concepcion about a six or seven run advantage defensively. Not exactly the same, but not too terribly different either.
Here's each player by season with some metrics ...
Code:
Season-by-Season
Year Davey WS Bert WS Davey WARP Bert WARP Davey OPS+ Bert OPS+
1964 ---- 6 ---- 1.7 ---- 86
1965 ---- 18 ---- 4.7 ---- 102
1966 ---- 22 ---- 5.6 ---- 98
1967 ---- 16 ---- 5.1 ---- 88
1968 ---- 29 ---- 9.5 ---- 115
1969 ---- 16 ---- 4.7 ---- 74
1970 5 26 1.4 8.9 73 114
1971 4 15 0.5 5.1 43 75
1972 6 21 2.8 8.1 59 84
1973 16 20 5.5 7.5 114 81
1974 25 22 9.9 7.3 106 112
1975 19 17 7.5 4.2 88 92
1976 23 19 9.9 6.5 107 87
1977 19 15 8.2 6.1 84 78
1978 25 3 8.3 0.9 114 37
1979 24 5 9.6 1.6 107 57
1980 17 4 5.8 0.9 84 74
1981 20 2 7.2 0.1 116 84
1982 17 ---- 7.9 ---- 97 ----
1983 8 4 3.6 1.1 61 101
1984 11 ---- 3.1 ---- 74 ----
1985 12 ---- 2.5 ---- 77 ----
1986 8 ---- 2.2 ---- 79 ----
1987 8 ---- 3.9 ---- 100 ----
1988 2 ---- 0.9 ---- 45 ----
Overall statistically, these two players are so close that it's virtually a wash. Depending on the preferred metric, one player comes out slightly ahead of the other player. But the differences are so slight that noise and imperfections pretty much swallow them up.
Who somebody chooses as the greater player really comes down to personal preferences, IMO. Frankly, I'll sacrifice a very limited amount of offensive production (i.e. whatever the very small difference between Campaneris and Concepcion really is) in exchange for having the guy who is arguably one of the top three or four defensive shortstops in the history of the game. The fact that Concepcion is one of the greatest defensive shortstops of all-time is the main reason why I support him for Cooperstown. Campaneris was a very similar player, but he wasn't anywhere near the greatest defensive shortstop.
All that means I'd take Davey over Bert, and I'm sure just about every other Reds fan out there would too.