AFAICT, as of commit a0a422c,  we have 2 different logics to evict outbound peers : lagging-chain (`ConsiderEviction`) and (`CheckForStaleTipAndEvictPeers`). The former to sanitize out lazy/buggy peers who have never sent us a valid header and are always staying behind our tip, the latter triggered in case of stale tip due to block variance to seek a better chain by rotating our outbound peers if we already reach an outbound limit (`EvictExtraOutboundPeers`).

Block-relay-only peers were introduced by #15719. Contrary to outbound full-relay peers who provided us at least a useful header, they're not protected by lagging-chain eviction.

We actually have a comment inside `ProcessHeadersMessage` indicating the contrary behavior. We should either document cleanly that block-relay-only aren't protected or effectively extend the scope of protection to them.

Hinted during #19724 review, see https://github.com/bitcoin/bitcoin/pull/19724#discussion_r475144532
CNodeState *state = State(nodeid);
    assert(state != nullptr);
    ProcessBlockAvailability(nodeid);
    const CBlockIndex* pindex = LookupBlockIndex(hash);
    if (pindex && pindex->nChainWork > 0) {
        
        if (state->pindexBestKnownBlock == nullptr || pindex->nChainWork >= state->pindexBestKnownBlock->nChainWork) {
            state->pindexBestKnownBlock = pindex;
        }
    } else {
        
        state->hashLastUnknownBlock = hash;
    }
}
/**
 * When a peer sends us a valid block, instruct it to announce blocks to us
 * using CMPCTBLOCK if possible by adding its nodeid to the end of
 * lNodesAnnouncingHeaderAndIDs, and keeping that list under a certain size by
 * removing the first element if necessary.
 */
static void MaybeSetPeerAsAnnouncingHeaderAndIDs(NodeId nodeid, CConnman& connman) EXCLUSIVE_LOCKS_REQUIRED(cs_main)