The reigning National League champions are planning an active defense of their crown. Rather than sit on their homegrown dynasty and hope it could sustain itself another year, the St. Louis Cardinals traded David Freese and Fernando Salas to the Los Angeles Angels for Peter Bourjos and Randal Grichuk, Friday, then signed free-agent shortstop Jhonny Peralta to a four-year, $53-million deal Sunday.

The Cardinals’ 2013 lineup, when everyone was healthy, looked like this:

1. Matt Carpenter – 2B
2. Carlos Beltran – RF
3. Allen Craig – 1B
4. Matt Holliday – LF
5. Yadier Molina – C
6. David Freese – 3B
7. Jon Jay – CF
8. Peter Kozma – SS

Prior to this pair of moves, the prospective 2014 lineup looked much the same, but with Beltran gone, and either Craig (with Matt Adams starting at first base) or top prospect Oscar Taveras in his place in right field. Now, however, things are shaken up a bit:

1. Matt Carpenter – 3B
2. Kolten Wong – 2B
3. Allen Craig – RF
4. Matt Holliday – LF
5. Yadier Molina – C
6. Jhonny Peralta – SS
7. Matt Adams – 1B
8. Peter Bourjos – CF

This assumes that Taveras will at least begin the season in Triple-A. It also slots two of the lineup’s three lefty bats into the top two spots in the order. It might well end up looking slightly different, for those reasons, but this is the gist.

It’s a much better lineup, on the whole. While you’ll hear a lot (and I even plan to write, briefly) about the massive upgrade from their 2013 catching situation that the Yankees made when they added Brian McCann this weekend, the jump from Pete Kozma (the worst hitter to play regularly on a good team in over 20 years) to Peralta has the largest relative impact potential of any move made so far this winter.

Peralta relies more than you would think he would on batting average on balls in play. Batters have BABIP skills; it’s not all luck. That does make him a high-variance hitter, though. He’s not elite as a slugger (though his power is average or better, especially for the position), or in his control of the strike zone.

For me, the major headline in evaluating Peralta is that he’s a fine, maybe even a tick above-average, defensive shortstop. That’s far removed from the popular conception of him, but the three major defensive metrics of note variously rate him as two, four or 25 runs better than average in his nearly four seasons as the Tigers’ shortstop. He’s a very thick athlete, and not an especially fast guy. PECOTA compares him most closely to Juan Uribe, Miguel Tejada and Carlos Guillen, all of which sound right. Like them, Peralta looks like a bad defensive shortstop, so people say he is one, even though he isn’t.

Peralta will be part of a much-improved defensive infield, even if he is not, individually, an upgrade over Kozma on defense. Freese had a nightmare of a season with the glove at third base last year, at 30 years of age, and also saw his power fade at the plate. The trade that sent him away gives Carpenter the chance to move back to his natural position, and Kolten Wong (a solid defender) the regular second-base gig.

That trade helps the defense in another way, too. Jon Jay is a step too slow to be a good defensive center fielder, and he doesn’t make up for it with any unusual aptitude for getting jumps or taking direct routes to the ball. Bourjos, two years Jay’s junior (and four years younger than Freese, and under team control one year longer than Freese, to boot), runs much better, and is generally considered a strong defender. While Jay, with his left-handed bat, will presumably get some action even now that Bourjos has arrived, that move makes the Cardinals better, just as Peralta taking over for Kozma does.

The Cards got some great performances from strange places last season. Carpenter’s age-27 breakout was awesome, but might not be fully replicable. Molina made a strong case for the NL MVP award for a second straight year, at 30, which only solidified him as a future Hall of Famer, but which shouldn’t lead us to deify Molina and ignore the very sharp aging curve that affects catchers beginning just at Molina’s age. Holliday isn’t a catcher, but will turn 34 in January. Beltran, now a free agent, is older than that. St. Louis needed to get younger and more well-rounded, and they did that. Their projected starting lineup next spring goes, by age, 28-23-29-34-31-32-24-27, which isn’t exactly bursting with youth, but looks a lot better than the 28-29-24-34-31-31-29-26 they had before, reliant as it was on the oldest of its members.

The biggest story here, though, might be what the Cardinals didn’t do. In addressing the glaring holes that showed up as they progressed through the 2013 postseason, they didn’t weaken their farm system. In fact, they strengthened it. Rather than trade from their wealth and depth of young pitching and polished positional prospects, as a frustrating number of people thought they would (and even should), they shed an aging spare part (Freese) in order to plug one hole, and signed an underrated free agent who fit well to plug the other. They don’t lose a draft pick for signing Peralta, and still have an extra one coming when Beltran signs elsewhere. They spent money, because they have plenty, and they held onto Wong, Taveras, Shelby Miller, Joe Kelly, Lance Lynn and their battery of young corner-outfield and third-base prospects.

They even added one to that corps, by getting Randal Grichuk thrown into the Freese-Bourjos trade. Grichuk is a free-swinging right-handed corner outfielder, and while scouting consensus pegs his ceiling in the fourth outfielder/fringe regular range, his power suggests impact potential. Over the last two seasons, at ages 20 and 21, he has slugged north ot .470 in the Florida State and Texas Leagues. That’s impressive. If the Cardinals, whose player-development processes are becoming the stuff of legend and who dominated the league with opposite-field doubles last season, can teach Grichuk a real, live plate approach, the Angels are going to recall this trade with a painful pang.

In short, it’s not that the Cardinals patched their holes. It’s how they did it. This is not the best-run organization in professional sports for nothing. The weekend demonstrated that.