my opinion is that the answer is yes...too much fish for a 29g. You didnt state what species but even with small dwarf cichlids a 29 can be too small if they are territorial. Depending on the species a single pair may do fine in a 29. For example, many breeders of Angels will keep a breeding pair in a 20 high or 29 (they need height) and it will work just fine but if the pairs are 4 inches now, just the tension between then in a 29 would probably be unworkable, especially if your intention is breeding them.
Think of it this way, irregardless of the number of gallons, a 29 has a foot print of basically 12 inches by 30 inches. That is 2 1/2 square feet of bottom. Now think about 4 4" fish end to end...that is 16 inches or over half the length of the tank. For even the most peaceful fish the math doesnt work out.