It's not the horses or chariots that are wrong; it's not jobs, bank accounts, medical professionals, insurance policies, education, friendships (or other typical sources of confidence). It's trusting them instead of and ahead of looking to, consulting, and trusting in God from beginning to end, and above all else.
"'Woe to those who go down to Egypt for help and rely on horses, who trust in chariots because they are many and in horsemen because they are very strong, but do not look to the Holy One of Israel or consult the Lord!'" (Isaiah 31:1)