Despite these problems, the party continued to grow in size, and in 1986 the CIA considered its military strength comparable to Lebanon's major militias. The total membership of Hezbollah and closely affiliated groups grew from "several hundred" in 1983 to 2,000–3,000 in 1984 and to a few thousand in 1985, and in mid-1986 the group massed 5,000 fighters for an event in the town of Baalbek in the Bekaa Valley. Hezbollah was numerically smaller than Amal in 1986, but trends were favoring Hezbollah. At this time, the organization had many part-time fighters and very few full-time members, making it sensitive to casualties. The organization's "skill in fighting the Israeli Army and Israel's proxy militia forces", as well as the corruption and inefficiency of Hezbollah's rival Amal, were critical in building credibility and public support. In south Lebanon, Amal was widely seen as "too moderate" and accommodating of Israel, leading many radicalized Shia to back Hezbollah. Hezbollah also received backing from pro-Hezbollah factions of Amal that had split from top Amal leadership. Assessments of Hezbollah's position at this time vary. The CIA assessed at the time that "Hizballah's policy of confronting Israel and its surrogates is working" and that Hezbollah held a "qualitative edge" in warfare over the SLA and Amal, while an independent review says that by 1987 Hezbollah's strategic position was deteriorating. On April 18, 1987, a Hezbollah human wave attack on a fortified SLA outpost failed and resulted in 24 dead, killing around 5% of the organization's full-time fighters in a single day. As a consequence of this setback and others like it, Hezbollah was forced to change its strategy. Outgunned by the Israelis and outspent by richer Lebanese sects and political parties, Hezbollah was forced to learn fast and reappraise its tactics, strategy, and organization.