Yeah we thought about that and chef and I thought we'd pick Eric. Karna is easily the better choice, she usually turns out to be my best character, but that's why we aren't choosing her. I never pick Eric, so it might be more interesting this way.
Toe-to-toe Eric (Pegasus) and Randolf (Baron) are fairly even stat-wise, but Eric wins in mobility and the Valkyrie/Mist Spear (for its range) is better than that earth axe you make out of mithral (I don't remember its name). I'm assuming you won't be using cursed weapons... in which case the Evil Axe is way better than the Devil Lance.
Edit: Found a chart on GameFAQs that might assist in decision-making.
Final Stats - If promoted at 20 with best weapon for character
HP MP ATT DEF AGI
------------------------------------------------------------------
Bowie 103.5 18.5 102.5 90.5 58
Sarah 88 67 106 73 59
Chester 102 0 0 75 65
Jaha 87 0 100 95 60
Kazin 80 84 66 58 85
Slade 94 55 98 83 72
Kiwi 40 0 96 99 55
Peter 107 0 120 88 56
May 66 0 90 60 63
Gerhalt 91 0 108 85 63
Luke 90 0 89 73 69
Rohde 82 0 90 85 51
Rick 89 0 94 89 73
Elric 89 0 88 67 58
Eric 108 0 103 89 75
Karna 104 84 109 61 68
Tyrin 79 84 73 61 71
Randolf 95 0 105 96 61
Janet 91 0 80 66 62
Higins 97 0 96 75 62
Taya 76 88 65 53 72
Skreech 90 0 92 70 65
Frayja 85 74 85 60 58
Jaro 95 0 94 70 72
Zynk 86 0 108 89 62
Gyan 92 0 100 101 53
Sheela 82 65 94 61 63
Claude 73 0 110 112 51
Chaz 85 90 70 63 58
Lemon 97 0 101 91 66
Chester's stats are missing for some reason.